Polyethylene for injection moldings

ABSTRACT

Polyethylene which comprises ethylene homopolymers and/or copolymers of ethylene with 1-alkenes and has a molar mass distribution width M w /M n  of from 3 to 30, a density of from 0.945 to 0.965 g/cm 3 , a weight average molar mass M w  of from 50 000 g/mol to 200 000 g/mol, a HLMI of from 10 to 300 g/10 min and has from 0.1 to 15 branches/1000 carbon atoms, wherein the 1 to 15% by weight of the polyethylene having the highest molar masses have a degree of branching of more than 1 branch of side chains larger than CH 3 /1000 carbon atoms, a process for its preparation, catalysts suitable for its preparation and also injection moldings in which this polyethylene is present.

This application is the U.S. national phase of International ApplicationPCT/EP2005/004412, filed Apr. 25, 2005, claiming priority to GermanPatent Application 102004020524.8 filed Apr. 26, 2004, and the benefitunder 35 U.S.C. 119(e) of U.S. Provisional Application No. 60/587,533,filed Jul. 13, 2004; the disclosures of International ApplicationPCT/EP2005/004412, German Patent Application 102004020524.8 and U.S.Provisional Application No. 60/587,533, each as filed, are incorporatedherein by reference.

DESCRIPTION

The present invention relates to a novel polyethylene, which comprisesethylene homopolymers and/or copolymers of ethylene with 1-alkenes andhas a molar mass distribution width M_(w)/M_(n) of from 3 to 30, adensity of from 0.945 to 0.965 g/cm³, a weight average molar mass M_(w)of from 50 000 g/mol to 200 000 g/mol, a HLMI of from 10 to 300 g/10 minand has from 0.1 to 15 branches/1000 carbon atoms, wherein the 1 to 15%by weight of the polyethylene having the highest molar masses have adegree of branching of more than 1 branch of side chains larger thanCH₃/1000 carbon atoms, a catalyst composition and a process for itspreparation, and also injection moldings in which this polyethylene ispresent.

Blends of different polyethylenes are known and used for the preparationof injection moldings with a high stress crack resistance as disclosedin DE-C 34 37 116.

In recent times, polyethylene blends have been used in injection moldingto produce many types of screw closures. It is advantageous if the screwclosures retain their dimension and shape during cooling after theinjection molding procedure, i.e. do not shrink (low shrinkage). Lowshrinkage coupled with retention of shape represent an importantproperty of plastics, which are to be used for example to produce screwclosures with accurate fit. Furthermore the injection molding process isusually easier to perform if the polyethylene molding compositions havegood flowability in the melt. Ever higher demands are made of themechanical strength of moldings comprising polyethylene. On the otherhand godd processability achieving high through-puts are required.

WO 00/71615 discloses injection molded containers from bimodalpolyethylene, having a density of from 0.950 to 0.98 g/cm³, acrystallinity of from 60 to 90%, consitsing of at least 2 polyethylenecomponents with different molar mass distribution and wherein at leastone component is a copolymer of ethylene. The polyethylene is obtainedvia a reactor cascade or by melt extrusion of the two components.

The known ethylene copolymer blends still leave something to be desiredin terms of the combination of good mechanical properties, highflowability of the melt and good optical properties.

It has surprisingly been found that this object can be achieved using aspecific catalyst composition by means of which a polyethylene havinggood mechanical properties, good processability and good opticalproperties can be prepared.

We have accordingly found a polyethylene which comprises ethylenehomopolymers and/or copolymers of ethylene with 1-alkenes and has amolar mass distribution width M_(w)/M_(n) of from 3 to 30, a density offrom 0.945 to 0.965 g/cm³, a weight average molar mass M_(w) of from 50000 g/mol to 200 000 g/mol, a HLMI of from 10 to 300 g/10 min and hasfrom 0.1 to 15 branches/1000 carbon atoms, wherein the 1 to 15% byweight of the polyethylene having the highest molar masses have a degreeof branching of more than 1 branch of side chains larger than CH₃/1000carbon atoms.

We have also found injection moldings, caps and closures in which thepolyethylene of the invention is present as a significant component.Furthermore, we have found the use of the polyethylenes of the inventionfor producing injection moldings.

We have also found a catalyst system for preparing the polyethylenes ofthe invention, the use of the catalyst system for the polymerization ofethylene and/or copolymerization of ethylene with 1-alkenes and aprocess for preparing the polyethylene of the invention bypolymerization of ethylene and/or copolymerization of ethylene with1-alkenes in the presence of the catalyst system.

The polyethylene of the invention has a molar mass distribution widthM_(w)/M_(n) in the range from 3 to 30, preferably from 5 to 20 andparticularly preferably from 6 to 15. The density of the polyethylene ofthe invention is in the range from 0.945 to 0.965 g/cm³, preferably from0.947 to 0.96 g/cm³ and particularly preferably in the range from 0.948to 0.955 g/cm³. The weight average molar mass M_(w) of the polyethyleneof the invention is in the range from 50 000 g/mol to 200 000 g/mol,preferably from 70 000 g/mol to 150 000 g/mol and particularlypreferably from 80 000 g/mol to 120 000 g/mol. The HLMI of thepolyethylene of the invention is in the range from 10 to 300 g/10 min,preferably from 50 to 200 g/10 min and particularly preferably in therange from 70 to 150 g/10 min. For the purposes of this invention, theexpression “HLMI” refers as known to the “high load melt index” and isdetermined at 190° C. under a load of 21.6 kg (190° C./21.6 kg) inaccordance with ISO 1133.

The density [g/cm³] was determined according to ISO 1183. Thedetermination of the molar mass distributions and the means Mn, Mw, andMw/Mn derived therefrom was carried out by means of high-temperature gelpermeation chromatography on a WATERS 150 C using a method based on DIN55672 and the following columns connected in series: 3× SHODEX AT 806MS, 1× SHODEX UT 807 and 1× SHODEX AT-G under the following conditions:solvent: 1,2,4-trichlorobenzene (stabilized with 0.025% by weight of2,6-di-tert-butyl-4-methylphenol), flow: 1 ml/min, 500 μl injectionvolume, temperature: 135° C., calibration using PE Standards. Evaluationwas carried out using WIN-GPC.

The polyethylene of the invention has from 0.1 to 15 branches/1000carbon atoms, preferably from 0.2 to 8 branches/1000 carbon atoms andparticularly preferably from 0.3 to 3 branches/1000 carbon atoms. Thebranches/1000 carbon atoms are determined by means of ¹³C-NMR, asdescribed by James. C. Randall, JMS-REV. Macromol. Chem. Phys., C29(2&3), 201-317 (1989), and refer to the total content of CH₃ groups/1000carbon atoms.

Furthermore, the polyethylene of the invention has 1 to 15% by weight ofthe polyethylene having the highest molar masses, preferably 2 to 12% byweight and particularly preferable 3 to 8% by weight have a degree ofbranching of more than 1 branch of side chains larger than CH₃/1000carbon atoms, preferably in the range from 2 to 20 branches of sidechains larger than CH₃/1000 carbon atoms and particularly preferably inthe range from 5 to 15 branches of side chains larger than CH₃/1000carbon atoms. This can be determined by sovent-nonsolvent fractionation,later called Holtrup fractionation as described in W. Holtrup, Makromol.Chem. 178, 2335 (1977) coupled with IR measurement of the differentfractions. Xylene and ethylene glycol diethyl ether at 130° C. were usedas solvents for the fractionation. 5 g of polyethylene were used andwere divided into 8 fractions. The fractions are subsequently examinedby ¹³C-NMR spectroscopy. The degree of branching in the various polymerfractions can be determined by means of ¹³C-NMR as described by James.C. Randall, JMS-REV. Macromol. Chem. Phys., C29 (2&3), 201-317 (1989).The polyethylene of the invention preferably has a CDBI of less than50%, in particular from 10 to 45%. The method of determining the CDBI isdescribed, for example in WO 93/03093. The TREF method is described, forexample, in Wild, Advances in Polymer Science, 98, p.1-47, 57 p. 153,1992. The CDBI is defined as the percentage by weight of the copolymermolecules having a comonomer content of ±25% of the mean total molarcomonomer content. Branches of side chains larger than CH₃ refers to thecontent of side chains/1000 carbon atoms without the end groups.

The molar mass distribution of the polyethylene of the invention can bemonomodal, bimodal or multimodal. In the present patent application, amonomodal molar mass distribution means that the molar mass distributionhas a single maximum. A bimodal molar mass distribution means, for thepurposes of the present patent application, that the molar massdistribution has at least two points of inflection on one flank startingfrom a maximum. The molar mass distribution is preferably monomodal orbimodal, in particular bimodal.

The 1 to 15% by weight of the polyethylene of the invention having thehighest molar masses, preferably the 2 to 12% by weight and particularlypreferable 3 to 8% by weight when fractionated by gel permeationchromatography (GPC), and then this fraction is examined by “analyticaltemperature rising elution fractionation technique” (TREF), preferablydo not show a high density polyethylene peak with a maximum above 80°C., preferably above 85° C. and particularly preferable above 90° C. Theconcentration of polymer in the fractions obtained at varioustemperatures is measured by means of infrared spectroscopy. The TREFresult can also be calibrated by means of preparatively isolatedpolyethylene fractions having a defined number of short chain branches.The TREF method is described, for example, in Wild, Advances in PolymerScience, 98, p.1-47, 57 p. 153, 1992.

When the polyethylene of the invention is examined by TREF, thefractions at a maximum above 80° C., preferably above 85° C. andparticularly preferable above 90° C., when examined by GPC preferablyshow only polyethylene with molar masses below 1 Mio g/mol as opposed topolyethylenes obtained with the usual Ziegler catalysts.

The polyethylene of the invention preferably has a degree of long chainbranching λ (lambda) of from 0 to 2 long chain branches/10 000 carbonatoms and particularly preferably from 0.1 to 1.5 long chain branches/10000 carbon atoms. The degree of long chain branching λ (lambda) wasmeasured by light scattering as described, for example, in ACS Series521, 1993, Chromatography of Polymers, Ed. Theodore Provder; Simon Pangand Alfred Rudin: Size-Exclusion Chromatographic Assessment ofLong-Chain Branch Frequency in Polyethylenes, page 254-269.

Preferably the 5-50% by weight of the polyethylene of the inventionhaving the lowest molar masses, preferably 10-40% by weight andparticularly preferably 15-30% by weight, have a degree of branching ofless than 10 branches/1000 carbon atoms. This degree of branching in thepart of the polyethylene having the lowest molar masses is preferablyfrom 0.01 to 9 branches/1000 carbon atoms and particularly preferablyfrom 0.1 to 6 branches/1000 carbon atoms. This can be determined bymeans of the Holtrup/¹³C-NMR method described. The branches/1000 carbonatoms are determined by means of ¹³C-NMR, as described by James. C.Randall, JMS-REV. Macromol. Chem. Phys., C29 (2&3), 201-317 (1989), andrefer to the total content of CH₃ groups/1000 carbon atoms

The polyethylene of the invention has at least 0.2 vinyl groups/1000carbon atoms, preferably from 0.7 to 5 vinyl groups/1000 carbon atomsand particularly preferably from 0.9 to 3 vinyl groups/1000 carbonatoms. The content of vinyl groups/1000 carbon atoms is determined bymeans of IR, ASTM D 6248-98. For the present purposes, the expressionvinyl groups refers to —CH═CH₂ groups; vinylidene groups and internalolefinic groups are not encompassed by this expression. Vinyl groups areusually attributed to a polymer termination reaction after an ethyleneinsertion, while vinylidene end groups are usually formed after a poymertermination reaction after a comonomer insertion.

The polyethylene of the invention preferably has from 0.01 to 20branches of side chains larger than CH₃/1000 carbon atoms, prefereablyside chains from C₂-C₆/1000 carbon atoms, preferably from 1 to 15branches of side chains larger than CH₃/1000 carbon atoms, prefereablyside chains from C₂-C₆/1000 carbon atoms and particularly preferablyfrom 2 to 8 branches of side chains larger than CH₃/1000 carbon atoms,prefereably side chains from C₂-C₆/1000 carbon atoms. The branches ofside chains larger than CH₃/1000 carbon atoms are determined by means of¹³C-NMR, as determined by James. C. Randall, JMS-REV. Macromol. Chem.Phys., C29 (2&3), 201-317 (1989), and refer to the total content of sidechains larger than CH₃ groups/1000 carbon atoms (without end groups). Itis particularly preferred in polyethylene with 1-butene, 1-hexene or1-octene as the α-olefin to have 0.01 to 20 ethyl, butyl or hexyl sidebranches/1000 carbon atoms, preferably from 1 to 15 ethyl, butyl orhexyl side branches/1000 carbon atoms and particularly preferably from 2to 8 ethyl, butyl or hexyl side branches/1000 carbon atoms. This refersto the content of ethyl, butyl or hexyl side chains/1000 carbon atomswithout the end groups.

In the polyethylene of the invention, the part of the polyethylenehaving a molar mass of less than 10 000 g/mol, preferably less than 20000, preferably has a degree of branching of from 0 to 1.5 branches ofside chains larger than CH₃/1000 carbon atoms, prefereably side chainsfrom C₂-C₆/1000 carbon atoms. Particular preference is given to the partof the polyethylene having a molar mass of less than 10 000 g/mol,preferably less than 20 000, having a degree of branching of from 0.1 to0.9 branches of side chains larger than CH₃/1000 carbon atoms,prefereably side chains from C₂-C₆/1000 carbon atoms. Preferably thepolyethylene of the invention with 1-butene, 1-hexene or 1-octene as the1-alkene, the part of the polyethylene having a molar mass of less than10 000 g/mol, preferably less than 20 000, preferably has a degree offrom 0 to 1.5 ethyl, butyl or hexyl branches of side chains/1000 carbonatoms. Particular preference is given to the part of the polyethylenehaving a molar mass of less than 10 000 g/mol, preferably less than 20000, having a degree of branching of from 0.1 to 0.9 ethyl, butyl orhexyl branches of side chains/1000 carbon atoms. This too, can bedetermined by means of the Holtrup/¹³C-NMR method described.

Furthermore, it is preferred that at least 70% of the branches of sidechains larger than CH₃ in the polyethylene of the invention are presentin the 50% by weight of the polyethylene having the highest molarmasses. This too can be determined by means of the Holtrup/¹³C-NMRmethod described.

The polyethylene of the invention preferably has a mixing qualitymeasured in accordance with ISO 13949 of less than 3, in particular from0 to 2.5. This value is based on the polyethylene taken directly fromthe reactor, i.e. the polyethylene powder without prior melting in anextruder. This polyethylene powder is preferably obtainable bypolymerization in a single reactor.

As 1-alkenes, which are the comonomers which can be present in theethylene copolymers, either individually or in a mixture with oneanother, in addition to ethylene in the ethylene copolymer part of thepolyethylene of the invention, it is possible to use all 1-alkeneshaving from 3 to 12 carbon atoms, e.g. propene, 1-butene, 1-pentene,1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene and 1-decene. Theethylene copolymer preferably comprises 1-alkenes having from 4 to 8carbon atoms, e.g. 1-butene, 1-pentene, 1-hexene, 4-methylpentene or1-octene, in copolymerized form as comonomer unit. Particular preferenceis given to using 1-alkenes selected from the group consisting of1-butene, 1-hexene and 1-octene. The polyethylene of the inventioncomprises preferentially 0.01 to 5% by weight, preferably 0.1 to 3 byweight of comonomer.

The polyethylene of the invention can further comprise of from 0 to 6%by weight, preferably 0.1 to 1 by weight of auxiliaries and/or additivesknown per se, e.g. processing stabilizers, stabilizers against theeffects of light and heat, customary additives such as lubricants,antioxidants, antiblocking agents and antistatics, and also, ifappropriate, dyes. A person skilled in the art will be familiar with thetype and amount of these additives.

Furthermore, it has been found that the processing properties of thepolyethylenes of the invention can be improved further by incorporationof small amounts of fluoroelastomers or thermoplastic polyesters. Suchfluoroelastomers are known as such as processing aids and arecommercially available, for example, under the trade names Viton® andDynamar® (cf. also, for example, U.S. Pat. No. 3,125,547). They arepreferably added in amounts of from 10 to 1000 ppm, particularlypreferably from 20 to 200 ppm, based on the total mass of the polymerblend according to the invention.

In general mixing of the additives and the polyethylene of the inventioncan be carried out by all known methods. It can be done, for example, byintroducing the powder components into a granulation apparatus, e.g. atwin-screw kneader (ZSK), Farrel kneader or Kobe kneader. The granulatedmixture can also be processed directly on a film production plant.

We have also found the use of the polyethylenes of the invention forproducing injection moldings, and injection moldings, preferably screwclosures, caps, tube shoulders and engineering parts in which thepolyethylene of the invention is present as a significant component.

Injection moldings, screw closures and caps, tube shoulders andengineering parts in which the polyethylene of the invention is presentas a significant component are ones which contain from 50 to 100% byweight, preferably from 60 to 90% by weight, of the polyethylene of theinvention, based on the total polymer material used for manufacture. Inparticular, injection moldings, screw closures and caps in which one ofthe layers contains from 50 to 100% by weight of the polyethylene of theinvention are also included.

The polyethylene and the injection moldings of the invention with athickness of 1 mm have preferably a haze, as determined according toASTM D 1003-00 on a BYK Gardener Haze Guard Plus Device on at least 5pieces of film 10×10 cm below 94%, preferably of from 10 to 92% andparticularly prefarbly of from 50 to 91%. The stress crack resistance(full notch creep test (FNCT)) of the polyethylene and injectionmoldings as determined according to ISO DIS2 16770 at a pressure of 3.5Mbar at 80° C. in a 2% by weight solution of Akropal N (N=10) in water,is preferably at least 5 h, preferably of from 6 to 80 h andparticularly prefarbly of from 7 to 20 h. The polyethylene and theinjection moldings of the invention with a thickness of 1 mm havepreferably an impact resistance as determined according to theinstrument falling weight impact test according to ISO 6603 at −20° C.of at least 12 J.

The polyethylene can be processed on conventional injection moldingmachines. The finish on the moldings obtained is homogeneous and can beimproved further by increasing the rate of injection or raising themould temperature.

The flow properties under process conditions were determined with thespiral flow test. The polyethylene is injected at a defined temperature,pressure and screw speed into a spiral mould to obtain coils withvarious wall thicknesses. The length of the coil obtained can beregarded as a measure for the flow. The spiral flow test was measured ona Demag ET100-310 with a closing pressure of 100 t and a 3 mm die.

The dimension and form stability of the polyethylene of the inventionwas tested by inection molding at 180 to 270° C. screw caps with screwdiameter 28.2 mm. The caps were cooled and the screw diameter of 50samples measured, the average calculated and compared to the originalscrew diameter. The samples were furthermore visually inspected for formand dimension stability.

The polyethylene of the invention showed high flow properties, withspiral lengths above 40 cm, measured at stock temperature of 250° C., aninjection pressure of 1000 bar, screw speed 90 mm/s, mold temperature of30° C. and wall thickness 2 mm.

Injection molding, preferably closures, caps and screw closures andcaps, tube shoulders and engineering parts in which the polyethylene ofthe invention is present as a significant component are ones whichcontain from 50 to 100% by weight, preferably from 60 to 90% by weight,of the polyethylene of the invention, based on the total polymermaterial used for manufacture. The screw caps and closures arepreferably used for bottles, preferably bottles for beverages.

The polyethylene of the invention is obtainable using the catalystsystem of the invention and in particular its preferred embodiments.

The present invention further provides a catalyst composition comprisingat least two different polymerization catalysts of which A) is at leastone polymerization catalyst based on a monocyclopentadienyl complex of ametal of groups 4-6 of the Periodic Table of the Elements whosecyclopentadienyl system is substituted by an uncharged donor (A1) or ahafnocene (A2) and B) is at least one polymerization catalyst based onan iron component having a tridentate ligand bearing at least two ortho,ortho-disubstituted aryl radicals (B).

The invention further provides a process for the polymerization ofolefins in the presence of the catalyst composition of the invention.

For the purposes of the present invention, an uncharged donor is anuncharged functional group containing an element of group 15 or 16 ofthe Periodic Table.

Hafnocene catalyst components are, for example, cyclopentadienylcomplexes. The cyclopentadienyl complexes can be, for example, bridgedor unbridged biscyclopentadienyl complexes as described, for example, inEP 129 368, EP 561 479, EP 545 304 and EP 576 970, monocyclopentadienylcomplexes such as bridged amidocyclopentadienyl complexes described, forexample, in EP 416 815, multinuclear cyclopentadienyl complexes asdescribed in EP 632 063, pi-ligand-substituted tetrahydropentalenes asdescribed in EP 659 758 or pi-ligand-substituted tetrahydroindenes asdescribed in EP 661 300.

Preference is given to monocyclopentadienyl complexes (A1) containingthe following structural feature of the general formula Cp-Y_(m)M^(A)(I), where the variables have the following meanings:

-   -   Cp is a cyclopentadienyl system,    -   Y is a substituent which is bound to Cp and contains at least        one uncharged donor containing at least one atom of group 15 or        16 of the Periodic Table,    -   M^(A) is titanium, zirconium, hafnium, vanadium, niobium,        tantalum, chromium, molybdenum or tungsten, in particular        chromium, and    -   m is 1, 2 or 3.

Suitable monocyclopentadienyl complexes (A1) contain the structuralelement of the general formula Cp-Y_(m)M^(A) (I), where the variablesare as defined above. Further ligands can therefore be bound to themetal atom M^(A). The number of further ligands depends, for example, onthe oxidation state of the metal atom. These ligands are not furthercyclopentadienyl systems. Suitable ligands include monoanionic anddianionic ligands as have been described, for example, for X. Inaddition, Lewis bases such as amines, ethers, ketones, aldehydes,esters, sulfides or phosphines can also be bound to the metal center M.The monocyclopentadienyl complexes can be in monomeric, dimeric oroligomeric form. The monocyclopentadienyl complexes are preferably inmonomeric form.

M^(A) is a metal selected from the group consisting of titanium,zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenumand tungsten. The oxidation state of the transition metals M^(A) incatalytically active complexes is usually known to those skilled in theart. Chromium, molybdenum and tungsten are very probably present in theoxidation state +3, zirconium and hafnium in the oxidation state +4 andtitanium in the oxidation state +3 or +4. However, it is also possibleto use complexes whose oxidation state does not correspond to that ofthe active catalyst. Such complexes can then be appropriately reduced oroxidized by means of suitable activators. M^(A) is preferably titaniumin the oxidation state 3, vanadium, chromium, molybdenum or tungsten.Particular preference is given to chromium in the oxidation states 2, 3and 4, in particular 3.

m can be 1, 2 or 3, i.e. 1, 2 or 3 donor groups Y may be bound to Cp,with these being able to be identical or different when 2 or 3 groups Yare present. Preference is given to only one donor group Y being boundto Cp (m=1).

The uncharged donor Y is an uncharged functional group containing anelement of group 15 or 16 of the Periodic Table, e.g. an amine, imine,carboxamide, carboxylic ester, ketone (oxo), ether, thioketone,phosphine, phosphite, phosphine oxide, sulfonyl, sulfonamide orunsubstituted, substituted or fused, partially unsaturated heterocyclicor heteroaromatic ring systems. The donor Y can be boundintermolecularly or intramolecularly to the transition metal M^(A) ornot be bound to it. The donor Y is preferably bound intramolecularly tothe metal center M^(A). Particular preference is given tomonocyclopentadienyl complexes containing the structural element of thegeneral formula Cp—Y—M^(A).

Cp is a cyclopentadienyl system which may be substituted in any wayand/or be fused with one or more aromatic, aliphatic, heterocyclic orheteroaromatic rings, with 1, 2 or 3 substituents, preferably 1substituent, being formed by the group Y and/or 1, 2 or 3 substituents,preferably 1 substituent being substituted by the group Y and/or thearomatic, aliphatic, heterocyclic or heteroaromatic fused-on ringbearing 1, 2 or 3 substituents, preferably 1 substituent. Thecyclopentadienyl skeleton itself is a C₅ ring system having 6 πelectrons, in which one of the carbon atoms may also be replaced bynitrogen or phosphorus, preferably phosphorus. Preference is given tousing C₅ ring systems without replacement by a heteroatom. Thiscyclopentadienyl skeleton can be, for example, fused with aheteroaromatic containing at least one atom from the group consisting ofN, P, O and S or with an aromatic. In this context, fused means that theheterocycle and the cyclopentadienyl skeleton share two atoms,preferably carbon atoms. The cyclopentadienyl system is bound to M^(A).

Particularly well-suited monocyclopentadienyl complexes (A1) are ones inwhich Y is formed by the group —Z_(k)—A— and together with thecyclopentadienyl system Cp and M^(A) forms a monocyclopentadienylcomplex containing the structural element of the general formulaCp—Z_(k)—A—M^(A) (II), where the variables have the following meanings:

-   -   Cp—Z_(k)—A is

where the variables have the following meanings:

-   -   E^(1A)-E^(5A) are each carbon or not more than one E^(1A) to        E^(5A) phosphorus,    -   R^(1A)-R^(4A) are each, independently of one another, hydrogen,        C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, C₆ ⁻C₂₂-aryl, alkylaryl having        from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon        atoms in the aryl radical, NR^(5A) ₂, N(SiR^(5A) ₃)₂, OR^(5A),        OSiR^(5A) ₃, SiR^(5A) ₃, BR^(5A) ₂, where the organic radicals        R^(1A)-R^(4A) may also be substituted by halogens and two        vicinal radicals R^(1A)-R^(4A) may also be joined to form a        five-, six- or seven-membered ring, and/or two vicinal radicals        R^(1A)-R^(4A) are joined to form a five-, six- or seven-membered        heterocycle containing at least one atom from the group        consisting of N, P, O and S,    -   the radicals R^(5A) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part and two geminal radicals R^(5A)        may also be joined to form a five- or six-membered ring,    -   Z is a divalent bridge between A and Cp which is selected from        the following group

where

-   -   L^(1A)-L^(3A) are each, independently of one another, silicon or        germanium,    -   R^(6A)-R^(11A) are each, independently of one another, hydrogen,        C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆ ⁻C₂₀-aryl, alkylaryl having        from 1 to 10 carbon atoms in the alkyl part and 6-20 carbon        atoms in the aryl part or SiR^(12A) ₃, where the organic        radicals R^(6A)-R^(11A) may also be substituted by halogens and        two geminal or vicinal radicals R^(6A)-R^(11A) may also be        joined to form a five- or six-membered ring and    -   the radicals R^(12A) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl or alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part, C₁-C₁₀-alkoxy or C₆-C₁₀-aryloxy        and two radicals R^(12A) may also be joined to form a five- or        six-membered ring, and    -   A is an uncharged donor group containing one or more atoms of        group 15 and/or 16 of the Periodic Table of the Elements,        preferably an unsubstituted, substituted or fused,        heteroaromatic ring system,    -   M^(A) is a metal selected from the group consisting of titanium        in the oxidation state 3, vanadium, chromium, molybdenum and        tungsten, in particular chromium, and    -   k is 0 or 1.

In preferred cyclopentadienyl systems Cp, all E^(1A) to E^(5A) arecarbon.

The polymerization behavior of the metal complexes can be influenced byvarying the substituents R^(1A)-R^(4A). The number and type ofsubstituents can influence the accessibility of the metal atom M for theolefins to be polymerized. In this way, it is possible to modify theactivity and selectivity of the catalyst in respect of various monomers,in particular bulky monomers. Since the substituents can also influencethe rate of termination reactions of the growing polymer chain, themolecular weight of the polymers formed can also be altered in this way.The chemical structure of the substituents R^(1A) to R^(4A) cantherefore be varied within a wide range in order to achieve the desiredresults and to obtain a tailored catalyst system. Possible carboorganicsubstituents R^(1A)-R^(4A) are, for example, the following: hydrogen,C₁-C₂₂-alkyl which may be linear or branched, e.g. methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl,n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, 5- to 7-memberedcycloalkyl which may in turn bear a C₁-C₁₀-alkyl group and/orC₆-C₁₀-aryl group as substituent, e.g. cyclopropyl cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl orcyclododecyl, C₂-C₂₂-alkenyl which may be linear, cyclic or branched andin which the double bond may be internal or terminal, e.g. vinyl,1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl,cyclohexenyl, cyclooctenyl or cyclooctadienyl, C₆-C₂₂-aryl which may besubstituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl,anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5- or2,6-dimethylphenyl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or3,4,5-trimethylphenyl, or arylalkyl which may be substituted by furtheralkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or 2-ethylphenyl,where two radicals R^(1A) to R^(4A) may also be joined to form a 5-, 6-or 7-membered ring and/or two vicinal radicals R^(1A)-R^(4A) may bejoined to form a five-, six- or seven-membered heterocycle containing atleast one atom from the group consisting of N, P, O and S and/or theorganic radicals R^(1A)-R^(4A) may also be substituted by halogens suchas fluorine, chlorine or bromine. Furthermore, R^(1A)-R^(4A) may beamino NR^(5A) ₂ or N(SiR^(5A) ₃)₂, alkoxy or aryloxy OR^(5A), forexample dimethylamino, N-pyrrolidinyl, picolinyl, methoxy, ethoxy orisopropoxy. The radicals R^(5A) in organosilicone substituents SiR^(5A)₃ can be the same carboorganic radicals as described above forR^(1A)-R^(4A), where two radicals R^(5A) may also be joined to form a 5-or 6-membered ring, e.g. trimethylsilyl, triethylsilyl,butyldimethylsilyl, tributylsilyl, tritert-butylsilyl, triallylsilyl,triphenylsilyl or dimethylphenylsilyl. These SiR^(5A) ₃ radicals mayalso be joined to the cyclopentadienyl skeleton via an oxygen ornitrogen, for example trimethylsilyloxy, triethylsilyloxy,butyldimethylsilyloxy, tributylsilyloxy or tritert-butylsilyloxy.Preferred radicals R^(1A)-R^(4A) are hydrogen, methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl,n-octyl, vinyl, allyl, benzyl, phenyl, orthodialkyl- or-dichloro-substituted phenyls, trialkyl- or trichloro-substitutedphenyls, naphthyl, biphenyl and anthranyl. Possible organosiliconsubstituents are, in particular, trialkylsilyl groups having from 1 to10 carbon atoms in the alkyl radical, in particular trimethylsilylgroups.

Two vicinal radicals R^(1A)-R^(4A) together with the E^(1A)-E^(5A)bearing them may form a heterocycle, preferably heteroaromatic,containing at least one atom from the group consisting of nitrogen,phosphorus, oxygen and sulfur, particularly preferably nitrogen and/orsulfur, with the E^(1A)-E^(5A) present in the heterocycle orheteroaromatic preferably being carbons. Preference is given toheterocycles and heteroaromatics having a ring size of 5 or 6 ringatoms. Examples of 5-membered heterocycles which may contain from one tofour nitrogen atoms and/or a sulfur or oxygen atom as ring atoms inaddition to carbon atoms are 1,2-dihydrofuran, furan, thiophene,pyrrole, isoxazole, 3-isothiazole, pyrazole, oxazole, thiazole,imidazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole,1,2,3-triazole and 1,2,4-triazole. Examples of 6-membered heteroarylgroups which may contain from one to four nitrogen atoms and/or aphosphorus atom are pyridine, phosphabenzene, pyridazine, pyrimidine,pyrazine, 1,3,5-triazine 1,2,4-triazine or 1,2,3-triazine. The5-membered and 6-membered heterocycles may also be substituted byC₁-C₁₀-alkyl, C₆-C₁₀-aryl, alkylaryl having from 1 to 10 carbon atoms inthe alkyl part and 6-10 carbon atoms in the aryl part, trialkylsilyl orhalogens such as fluorine, chlorine or bromine, dialkylamide,alkylarylamide, diarylamide, alkoxy or aryloxy or be fused with one ormore aromatics or heteroaromatics. Examples of benzo-fused 5-memberedheteroaryl groups are indole, indazole, benzofuran, benzothiophene,benzothiazole, benzoxazole and benzimidazole. Examples of benzo-fused6-membered heteroaryl groups are chroman, benzopyran, quinoline,isoquinoline, cinnoline, phthalazine, quinazoline, quinoxaline,1,10-phenanthroline and quinolizine. Naming and numbering of theheterocycles has been taken from Lettau, Chemie der Heterocyclen, 1stedition, VEB, Weinheim 1979. The heterocycles/heteroaromatics arepreferably fused with the cyclopentadienyl skeleton via a C—C doublebond of the heterocycle/heteroaromatic. Heterocycles/heteroaromaticshaving one heteroatom are preferably 2,3- or b-fused.

Cyclopentadienyl systems Cp having a fused-on heterocycle are, forexample, thiapentalene, 2-methylthiapentalene, 2-ethylthiapentalene,2-isopropylthiapentalene, 2-n-butylthiapentalene,2-tert-butylthiapentalene, 2-trimethylsilylthiapentalene,2-phenylthiapentalene, 2-naphthylthiapentalene, 3-methylthiopentalene,4-phenyl-2,6-dimethyl-1-thiopentalene,4-phenyl-2,6-diethyl-1-thiopentalene,4-phenyl-2,6-diisopropyl-1-thiopentalene,4-phenyl-2,6-di-n-butyl-1-thiopentalene,4-phenyl-2,6-ditrimethylsilyl-1-thiopentalene, azapentalene,2-methylazapentalene, 2-ethylazapentalene, 2-isopropylazapentalene,2-n-butylazapentalene, 2-trimethylsilylazapentalene,2-phenylazapentalene, 2-naphthylazapentalene,1-phenyl-2,5-dimethyl-1-azapentalene,1-phenyl-2,5-diethyl-1-azapentalene,1-phenyl-2,5-di-n-butyl-1-azapentalene,1-phenyl-2,5-di-tert-butyl-1-azapentalene,1-phenyl-2,5-di-trimethylsilyl-1-azapentalene,1-tert-butyl-2,5-dimethyl-1-azapentalene, oxapentalene,phosphapentalene, 1-phenyl-2,5-dimethyl-1-phosphapentalene,1-phenyl-2,5-diethyl-1-phosphapentalene,1-phenyl-2,5-di-n-butyl-1-phosphapentalene,1-phenyl-2,5-di-tert-butyl-1-phosphapentalene,1-phenyl-2,5-di-trimethylsilyl-1-phosphapentalene,1-methyl-2,5-dimethyl-1-phosphapentalene,1-tert-butyl-2,5-dimethyl-1-phosphapentalene,7-cyclopenta-[1,2]thiophene[3,4]cyclopentadiene or7-cyclopenta[1,2]pyrrol[3,4]cyclopentadiene.

In further preferred cyclopentadienyl systems Cp, the four radicalsR^(1A)-R^(4A), i.e. the two pairs of vicinal radicals, form twoheterocycles, in particular heteroaromatics. The heterocyclic systemsare the same as those described above.

Cyclopentadienyl systems Cp having two fused heterocycles are, forexample, 7-cyclopentadithiophene, 7-cyclopentadipyrrole or7-cyclopentadiphosphole.

The synthesis of such cyclopentadienyl systems having a fused-onheterocycle is described, for example, in the abovementioned WO98/22486. In “metalorganic catalysts for synthesis and polymerisation”,Springer Verlag 1999, Ewen et al., p. 150 ff describe further synthesesof these cyclopentadienyl systems.

Particularly preferred substituents R^(1A)-R^(4A) are the carboorganicsubstituents described above and the carboorganic substituents whichform a cyclic fused ring system, i.e. together with theE^(1A)-E^(5A)-cyclopentadienyl skeleton, preferably aC₅-cyclopentadienyl skeleton, form, for example, an unsubstituted orsubstituted indenyl, benzindenyl, phenanthrenyl, fluorenyl ortetrahydroindenyl system, and also, in particular, their preferredembodiments.

Examples of such cyclopentadienyl systems (without the group —Z—A—,which is preferably located in the 1 position) are3-methylcyclopentadienyl, 3-ethylcyclopentadienyl,3-isopropylcyclopentadienyl, 3-tert-butylcyclopentadienyl,dialkylalkylcyclopentadienyl such as tetrahydroindenyl,2,4-dimethylcyclopentadienyl or 3-methyl-5-tert-butylcyclopentadienyl,trialkylcyclopentadienyl such as 2,3,5-trimethylcyclopentadienyl ortetraalkylcyclopentadienyl such as 2,3,4,5-tetramethylcyclopentadienyl,and also indenyl, 2-methylindenyl, 2-ethylindenyl, 2-isopropylindenyl,3-methylindenyl, benzindenyl and 2-methylbenzindenyl. The fused ringsystem may bear further C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl,alkylaryl having from 1 to 10 carbon atoms in the alkyl part and 6-20carbon atoms in the aryl part, NR^(5A) ₂, N(SiR^(5A) ₃)₂, OR^(5A),OSiR^(5A) ₃ or SiR^(5A) ₃, e.g. 4-methylindenyl, 4-ethylindenyl,4-isopropylindenyl, 5-methylindenyl, 4-phenylindenyl,5-methyl-4-phenylindenyl, 2-methyl-4-phenylindenyl or 4-naphthylindenyl.

In a particularly preferred embodiment, one of the substituentsR^(1A)-R^(4A) , preferably R^(2A), is a C₆-C₂₂-aryl or an alkylarylhaving from 1 to 10 carbon atoms in the alkyl part and 6-20 carbon atomsin the aryl part, preferably C₆-C₂₂-aryl such as phenyl, naphthyl,biphenyl, anthracenyl or phenanthrenyl, where the aryl may also besubstituted by N-, P-, O- or S-containing substituents, C₁-C₂₂-alkyl,C₂-C₂₂-alkenyl, halogens or haloalkyls or haloaryls having 1-10 carbonatoms, for example o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5- or2,6-dimethylphenyl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or3,4,5-trimethylphenyl, o-, m-, p-dimethylaminophenyl, o-, m-,p-methoxyphenyl, o-, m-, p-fluorophenyl, o-, m-, p-chlorophenyl, o-, m-,p-trifluoromethylphenyl, 2,3-, 2,4-, 2,5- or 2,6-difluorophenyl, 2,3-,2,4-, 2,5- or 2,6-dichlorophenyl or 2,3-, 2,4-, 2,5- or2,6-di(trifluoromethyl)phenyl. The N-, P-, O- or S-containingsubstituents, C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, halogens or haloalkyls orhaloaryls having 1-10 carbon atoms as substituents on the aryl radicalare preferably located in the para position relative to the bond to thecyclopentadienyl ring. The aryl substituent can be bound in the vicinalposition relative to the substituent —Z—A or the two substituents arelocated relative to one another in the 1,3 positions on thecyclopentadienyl ring. —Z—A and the aryl substituent are preferablypresent in the 1,3 positions relative to one another on thecyclopentadienyl ring.

As in the case of the metallocenes, the monocyclopentadienyl complexes(A1) can be chiral. Thus, one of the substituents R^(1A)-R^(4A) of thecyclopentadienyl skeleton can have one or more chiral centers or thecyclopentadienyl system Cp itself can be enantiotopic so that chiralityis induced only when it is bound to the transition metal M (for theformalism regarding chirality in cyclopentadienyl compounds, see R.Halterman, Chem. Rev. 92, (1992), 965-994).

The bridge Z between the cyclopentadienyl system Cp and the unchargeddonor A is a divalent organic bridge (k=1) which preferably consists ofcarbon- and/or silicon- and/or boron-containing bridge members. Theactivity of the catalyst can be influenced by changing the length of thelinkage between the cyclopentadienyl system and A. Z is preferably boundto the cyclopentadienyl skeleton next to the fused-on heterocycle orfused-on aromatic. Thus, if the heterocycle or aromatic is fused on inthe 2,3 positions of the cyclopentadienyl skeleton, then Z is preferablylocated in the 1 or 4 position of the cyclopentadienyl skeleton.

Possible carboorganic substituents R^(6A)-R^(11A) on the linkage Z are,for example, the following: hydrogen, C₁-C₂₀-alkyl which may be linearor branched, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl orn-dodecyl, 5- to 7-membered cycloalkyl which may in turn bear aC₆-C₁₀-aryl group as substituent, e.g. cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl orcyclododecyl, C₂-C₂₀-alkenyl which may be linear, cyclic or branched andin which the double bond may be internal or terminal, e.g. vinyl,1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl,cyclohexenyl, cyclooctenyl or cyclooctadienyl, C₆-C₂₀-aryl which may besubstituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl,anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5- or2,6-dimethylphen-1-yl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or3,4,5-trimethylphen-1-yl, or arylalkyl which may be substituted byfurther alkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or2-ethylphenyl, where two R^(6A) to R^(11A) may also be joined to form a5- or 6-membered ring, for example cyclohexane, and the organic radicalsR^(6A)-R^(11A) may also be substituted by halogens such as fluorine,chlorine or bromine, for example pentafluorophenyl orbis-3,5-trifluoromethylphen-1-yl and alkyl or aryl.

The radicals R^(12A) in organosilicon substitutents SiR^(12A) ₃ can bethe same radicals as mentioned above for R^(6A)-R^(11A), where tworadicals R^(12A) may also be joined to form a 5- or 6-membered ring,e.g. trimethylsilyl, triethylsilyl, butyldimethylsilyl, tributylsilyl,tritert-butylsilyl, triallylsilyl, triphenylsilyl ordimethylphenylsilyl. Preferred radicals R^(6A)-R^(11A) are hydrogen,methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl,n-pentyl, n-hexyl, n-heptyl, n-octyl, benzyl, phenyl, orthodialkyl- ordichloro-substituted phenyls, trialkyl- or trichloro-substitutedphenyls, naphthyl, biphenyl and anthranyl.

Particularly preferred substituents R^(6A) to R^(11A) are hydrogen,C₁-C₂₀-alkyl which may be linear or branched, e.g. methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl,n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, C₆-C₂₀-aryl which maybe substituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl,anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5- or2,6-dimethylphen-1-yl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or3,4,5-trimethylphen-1-yl, or arylalkyl which may be substituted byfurther alkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or2-ethylphenyl where two radicals R^(6A) to R^(11A) may also be joined toform a 5- or 6-membered ring, for example cyclohexane, and the organicradicals R^(6A)-R^(11A) may also be substituted by halogens such asfluorine, chlorine or bromine, in particular fluorine, for examplepentafluorophenyl or bis-3,5-trifluoromethylphen-1-yl and alkyl or aryl.Particular preference is given to methyl, ethyl, 1-propyl, 2-isopropyl,1-butyl, 2-tert-butyl, phenyl and pentafluorophenyl.

Z is preferably a goup —CR^(6A)R^(7A)—, —SiR^(6A)R^(7A)—, in particular—Si(CH₃)₂—, —CR^(6A)R^(7A)CR^(8A)R^(9A)—, —SiR^(6A)R^(7A)CR^(8A)R^(9A)—or substituted or unsubstituted 1,2-phenylene and in particular—CR^(6A)R^(7A)—. The preferred embodiments of the substituents R^(6A) toR^(11A) described above are likewise preferred embodiments here.Preference is given to —CR^(6A)R^(7A)— being a —CHR^(6A)—, —CH₂— or—C(CH₃)₂— group. The group —SiR^(6A)R^(7A)— in—L^(1A)R^(6A)R^(7A)CR^(8A)R^(9A)— can be bound to the cyclopentadienylsystem or to A. This group —SiR^(6A)R^(7A)— or a preferred embodimentthereof is preferably bound to Cp.

k is 0 or 1; in particular, k is 1 or when A is an unsubstituted,substituted or fused, heterocyclic ring system may also be 0. Preferenceis given to k being 1.

A is an uncharged donor containing an atom of group 15 or 16 of thePeriodic Table, preferably one or more atoms selected from the groupconsisting of oxygen, sulfur, nitrogen and phosphorus, preferablynitrogen and phosphorus. The donor function in A can bindintermolecularly or intramolecularly to the metal M^(A). The donor in Ais preferably bound intramolecularly to M. Possible donors are unchargedfunctional groups containing an element of group 15 or 16 of thePeriodic Table, e.g. amine, imine, carboxamide, carboxylic ester, ketone(oxo), ether, thioketone, phosphine, phosphite, phosphine oxide,sulfonyl, sulfonamide or unsubstituted, substituted or fused,heterocyclic ring systems. The attachment of A to the cyclopentadienylradical and Z can be carried out synthetically by, for example, a methodanalogous to that described in WO 00/35928.

A is preferably a group selected from among —OR^(13A)—, —SR^(13A)—,—NR^(13A)R^(14A)—, —PR^(13A)R^(14A)—. —C═NR^(13A)— and unsubstituted,substituted or fused heteroaromatic ring systems, in particular—NR^(13A)R^(14A)—, —C═NR^(13A)— and unsubstituted, substituted or fusedheteroaromatic ring systems.

R^(13A) and R^(14A) are each, independently of one another, hydrogen,C₁-C₂₀-alkyl which may be linear or branched, e.g. methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl,n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, 5- to 7-memberedcycloalkyl which may in turn bear a C₆-C₁₀-aryl group as substituent,e.g. cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl, cyclononyl or cyclododecyl, C₂-C₂₀-alkenyl which may belinear, cyclic or branched and in which the double bond may be internalor terminal, e.g. vinyl, 1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl,hexenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl or cyclooctadienyl,C₆-C₂₀-aryl which may be substituted by further alkyl groups, e.g.phenyl, naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl, 2,3-,2,4-, 2,5- or 2,6-dimethylphen-1-yl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-,2,4,6- or 3,4,5-trimethylphen-1-yl, alkylaryl which has from 1 to 10carbon atoms in the alkyl part and 6-20 carbon atoms in the aryl partand may be substituted by further alkyl groups, e.g. benzyl, o-, m-,p-methylbenzyl, 1- or 2-ethylphenyl or SiR^(15A) ₃, where the organicradicals R^(13A)-R^(14A) may also be substituted by halogens such asfluorine, chlorine or bromine or nitrogen-containing groups and furtherC₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having from 1 to 10carbon atoms in the alkyl part and 6-20 carbon atoms in the aryl part orSiR^(15A) ₃ groups and two vicinal radicals R^(13A)-R^(14A) may also bejoined to form a five- or six-membered ring and the radicals R^(15A) areeach, independently of one another, hydrogen, C₁-C₂₀-alkyl,C₂-C₂₀-alkenyl, C₆-C₂₀-aryl or alkylaryl having from 1 to 10 carbonatoms in the alkyl part and 6-20 carbon atoms in the aryl part and tworadicals R^(15A) may also be joined to form a five- or six-memberedring. NR^(13A)R^(14A) is an amide substituent. It is preferably asecondary amide such as dimethylamide, N-ethylmethylamide, diethylamide,N-methylpropylamide, N-methylisopropylamide, N-ethylisopropylamide,dipropylamide, diisopropylamide, N-methylbutylamide, N-ethylbutylamide,N-methyl-tert-butylamide, N-tert-butylisopropylamide, dibutylamide,di-sec-butylamide, diisobutylamide, tert-amyl-tert-butylamide,dipentylamide, N-methylhexylamide, dihexylamide,tert-amyl-tert-octylamide, dioctylamide, bis(2-ethylhexyl)amide,didecylamide, N-methyloctadecylamide, N-methyl-cyclohexylamide,N-ethylcyclohexylamide, N-isopropylcyclohexylamide,N-tert-butylcyclohexylamide, dicyclohexylamide, pyrrolidine, piperidine,hexamethylenimine, decahydroquinoline, diphenylamine, N-methylanilide orN-ethylanilide.

In the imino group —C═NR^(13A), R^(13A) is preferably a C₆-C₂₀-arylradical which may be substituted by further alkyl groups, e.g. phenyl,naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5-or 2,6-dimethylphen-1-yl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or3,4,5-trimethylphen-1-yl.

A is preferably an unsubstituted, substituted or fused heteroaromaticring system which can contain heteroatoms from the group consisting ofoxygen, sulfur, nitrogen and phosphorus in addition to ring carbons.Examples of 5-membered heteroaryl groups which may contain from one tofour nitrogen atoms or from one to three nitrogen atoms and/or a sulfuror oxygen atom as ring members in addition to carbon atoms are 2-furyl,2-thienyl, 2-pyrrolyl, 3-isoxazolyl, 5-isoxazolyl, 3-isothiazolyl,5-isothiazolyl, 1-pyrazolyl, 3-pyrazolyl, 5-pyrazolyl, 2-oxazolyl,4-oxazolyl, 5-oxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl,2-imidazolyl, 4-imidazolyl, 5-imidazolyl, 1,2,4-oxadiazol-3-yl,1,2,4-oxadiazol-5-yl, 1,3,4-oxadiazol-2-yl and 1,2,4-triazol-3-yl.Examples of 6-membered heteroaryl groups which may contain from one tofour nitrogen atoms and/or a phosphorus atom are 2-pyridinyl,2-phosphabenzenyl, 3-pyridazinyl, 2-pyrimidinyl, 4-pyrimidinyl,2-pyrazinyl, 1,3,5-triazin-2-yl and 1,2,4-triazin-3-yl,1,2,4-triazin-5-yl and 1,2,4-triazin-6-yl. The 5-membered and 6-memberedheteroaryl groups may also be substituted by C₁-C₁₀-alkyl, C₆-C₁₀-aryl,alkylaryl having from 1 to 10 carbon atoms in the alkyl part and 6-10carbon atoms in the aryl part, trialkylsilyl or halogens such asfluorine, chlorine or bromine or be fused with one or more aromatics orheteroaromatics. Examples of benzo-fused 5-membered heteroaryl groupsare 2-indolyl, 7-indolyl, 2-coumaronyl, 7-coumaronyl, 2-thionaphthenyl,7-thionaphthenyl, 3-indazolyl, 7-indazolyl, 2-benzimidazolyl and7-benzimidazolyl. Examples of benzo-fused 6-membered heteroaryl groupsare 2-quinolyl, 8-quinolyl, 3-cinnolyl, 8-cinnolyl, 1-phthalazyl,2-quinazolyl, 4-quinazolyl, 8-quinazolyl, 5-quinoxalyl, 4-acridyl,1-phenanthridyl and 1-phenazyl. Naming and numbering of the heterocycleshas been taken from L. Fieser and M. Fieser, Lehrbuch der organischenChemie, 3^(rd) revised edition, Verlag Chemie, Weinheim 1957.

Among these heteroaromatic systems A, particular preference is given tounsubstituted, substituted and/or fused six-membered heteroaromaticshaving 1, 2, 3, 4 or 5 nitrogen atoms in the heteroaromatic part, inparticular substituted and unsubstituted 2-pyridyl or 2-quinolyl. A istherefore preferably a group of the formula (IV)

, where

-   -   E^(6A)-E^(9A) are each, independently of one another, carbon or        nitrogen,    -   R^(16A)-R^(19A) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part or SiR^(20A) ₃, where the organic        radicals R^(16A)-R^(19A) may also be substituted by halogens or        nitrogen and further C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl,        alkylaryl having from 1 to 10 carbon atoms in the alkyl part and        6-20 carbon atoms in the aryl part or SiR^(20A) ₃ and two        vicinal radicals R^(16A)-R^(19A) or R^(16A) and Z may also be        joined to form a five- or six-membered ring and    -   the radicals R^(20A) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl or alkylaryl        having from 1 to 10 carbon atoms in the alkyl radical and 6-20        carbon atoms in the aryl radical and two radicals R^(20A) may        also be joined to form a five- or six-membered ring and    -   p is 0 when E^(6A)-E^(9A) nitrogen and is 1 when E^(6A)-E^(9A)        is carbon.

In particular, 0 or 1 E^(6A)-E^(9A) are nitrogen and the remainder arecarbon. A is particularly preferably a 2-pyridyl, 6-methyl-2-pyridyl,4-methyl-2-pyridyl, 5-methyl-2-pyridyl, 5-ethyl-2-pyridyl,4,6-dimethyl-2-pyridyl, 3-pyridazyl, 4-pyrimidyl, 2-pyrazinyl,6-methyl-2-pyrazinyl, 5-methyl-2-pyrazinyl, 3-methyl-2-pyrazinyl,3-ethylpyrazinyl, 3,5,6-trimethyl-2-pyrazinyl, 2-quinolyl,4-methyl-2-quinolyl, 6-methyl-2-quinolyl, 7-methyl-2-quinolyl,2-quinoxalyl or 3-methyl-2-quinoxalyl.

Owing to the ease of preparation, preferred combinations of Z and A arethose in which Z is unsubstituted or substituted 1,2-phenylene and A isNR^(16A)R^(17A) and those in which Z is —CHR^(6A)—, —CH₂—, —C(CH₃)₂ or—Si(CH₃)₂— and A is unsubstituted or substituted 2-quinolyl orunsubstituted or substituted 2-pyridyl. Systems without a bridge Z, inwhich k is 0, are also very particularly simple to synthesize. A ispreferably unsubstituted or substituted 8-quinolyl in this case. Inaddition, when k is 0, R^(2A) is preferably a C₆-C₂₂-aryl or analkylaryl having from 1 to 10 carbon atoms in the alkyl part and 6-20carbon atoms in the aryl part, preferably C₆-C₂₂-aryl such as phenyl,naphthyl, biphenyl, anthracenyl or phenanthrenyl, where the aryl mayalso be substituted by N-, P-, O- or S-containing substituents,C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, halogens or haloalkyls or haloaryls having1-10 carbon atoms.

The preferred embodiments described above for the variables are alsopreferred in these preferred combinations.

M^(A) is a metal selected from the group consisting of titanium in theoxidation state 3, vanadium, chromium, molybdenum and tungsten,preferably titanium in the oxidation state 3 and chromium. Particularpreference is given to chromium in the oxidation states 2, 3 and 4, inparticular 3. The metal complexes, in particular the chromium complexes,can be obtained in a simple manner by reacting the appropriate metalsalts, e.g. metal chlorides, with the ligand anion (e.g. using a methodanalogous to the examples in DE 197 10615).

Among the suitable monocyclopentadienyl complexes (A1), preference isgiven to those of the formula Cp—Y_(m)M^(A)X_(n) (V) where the variablesCp, Y, A, m and M^(A) are as defined above and their preferredembodiments are also preferred here and:

-   -   X^(A) are each, independently of one another, fluorine,        chlorine, bromine, iodine, hydrogen, C₁-C₁₀-alkyl,        C₂-C₁₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1-10 carbon atoms        in the alkyl part and 6-20 carbon atoms in the aryl part,        NR^(21A)R^(22A), OR^(21A), SR^(21A), SO₃R^(21A), OC(O)R^(21A),        CN, SCN, β-diketonate, CO, BF₄ ⁻, PF₆ ⁻ or a bulky        noncoordinating anion or two radicals X^(A) form a substituted        or unsubstituted diene ligand, in particular a 1,3-diene ligand,        and the radicals X^(A) may be joined to one another,    -   R^(21A)-R^(22A) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part, SiR^(23A) ₃, where the organic        radicals R^(21A)-R^(22A) may also be substituted by halogens or        nitrogen- and oxygen-containing groups and two radicals        R^(21A)-R^(22A) may also be joined to form a five- or        six-membered ring,    -   the radicals R^(23A) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part and two radicals R^(23A) may also        be joined to form a five- or six-membered ring and    -   n is 1, 2, or 3.

The embodiments and preferred embodiments described above for Cp, Y, Z,A, m and M^(A) also apply individually and in combination to thesepreferred monocyclopentadienyl complexes.

The ligands X^(A) result, for example, from the choice of theappropriate starting metal compounds used for the synthesis of themonocyclopentadienyl complexes, but can also be varied afterwards.Possible ligands X^(A) are, in particular, the halogens such asfluorine, chlorine, bromine or iodine, especially chlorine. Alkylradicals such as methyl, ethyl, propyl, butyl, vinyl, allyl, phenyl orbenzyl are also advantageous ligands X^(A). Further ligands X^(A) whichmay be mentioned, purely by way of example and in no way exhaustively,are trifluoroacetate, BF₄ ⁻, PF₆ ⁻ and also weakly coordinating ornoncoordinating anions (cf., for example, S. Strauss in Chem. Rev. 1993,93, 927-942), e.g. B(C₆F₅)₄ ⁻.

Amides, alkoxides, sulfonates, carboxylates and β-diketonates are alsoparticularly useful ligands X^(A). Variation of the radicals R^(21A) andR^(22A) enables, for example, physical properties such as solubility tobe finely adjusted. Possible carboorganic substituents R^(21A)-R^(22A)are, for example, the following: C₁-C₂₀-alkyl which may be linear orbranched, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl orn-dodecyl, 5- to 7-membered cycloalkyl which may in turn bear aC₆-C₁₀-aryl group as substituent, e.g. cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl orcyclododecyl, C₂-C₂₀-alkenyl which may be linear, cyclic or branched andin which the double bond may be internal or terminal, e.g. vinyl,1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl,cyclohexenyl, cyclooctenyl or cyclooctadienyl, C₆-C₂₀-aryl which may besubstituted by further alkyl groups and/or N- or O-containing radicals,e.g. phenyl, naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl,2,3-, 2,4-, 2,5- or 2,6-dimethylphenyl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-,2,4,6- or 3,4,5-trimethylphenyl, 2-methoxyphenyl,2-N,N-dimethylaminophenyl or arylalkyl, where the arylalkyl may besubstituted by further alkyl groups, e.g. benzyl, o-, m-,p-methylbenzyl, 1- or 2-ethyl-phenyl, where R^(21A) may also be joinedto R^(22A) to form a 5- or 6-membered ring and the organic radicalsR^(21A)-R^(22A) also be substituted by halogens such as fluorine,chlorine or bromine. Possible radicals R^(23A) in organosiliconsubstituents SiR^(23A) ₃ are the same radicals as have been mentionedabove for R^(21A)-R^(22A), where two R^(23A) may also be joined to forma 5- or 6-membered ring, e.g. trimethylsilyl, triethylsilyl,butyldimethylsilyl, tributylsilyl, triallylsilyl, triphenylsilyl ordimethylphenylsilyl. Preference is given to using C₁-C₁₀-alkyl such asmethyl, ethyl, n-propyl, n-butyl, tert-butyl, n-pentyl, n-hexyl,n-heptyl, n-octyl and also vinyl allyl, benzyl and phenyl as radicalsR^(21A) and R^(22A). Some of these substituted ligands X areparticularly preferably used since they are obtainable from cheap andreadily available starting materials. Thus, a particularly preferredembodiment is that in which X^(A) is dimethylamide, methoxide, ethoxide,isopropoxide, phenoxide, naphthoxide, triflate, p-toluenesulfonate,acetate or acetylacetonate.

The number n of ligands X^(A) depends on the oxidation state of thetransition metal M^(A). The number n can thus not be given in generalterms. The oxidation state of transition metals M^(A) in catalyticallyactive complexes is usually known to those skilled in the art. Chromium,molybdenum and tungsten are very probably present in the oxidation state+3, vanadium in the oxidation state +3 or +4. However, it is alsopossible to use complexes whose oxidation state does not correspond tothat of the active catalyst. Such complexes can then be appropriatelyreduced or oxidized by means of suitable activators. Preference is givento using chromium complexes in the oxidation state +3 and titaniumcomplexes in the oxidation state 3.

Preferred monocyclopentadienyl complexes (A1) of this type are1-(8-quinolyl)-3-phenylcyclopentadienylchromium(III) dichloride,1-(8-quinolyl)-3-(1-naphthyl)cyclopentadienylchromium(III) dichloride,1-(8-quinolyl)-3-(4-trifluoromethylphenyl)cyclopentadienylchromium(III)dichloride,1-(8-quinolyl)-2-methyl-3-phenylcyclopentadienylchromium(III)dichloride,1-(8-quinolyI)-2-methyl-3-(1-naphthyl)cyclopentadienylchromium(III)dichloride,1-(8-quinolyl)-2-methyl-3-(4-trifluoromethylphenyl)cyclopentadienylchromium(III)dichloride, 1-(8-quinolyl)-2-phenylindenylchromium(III) dichloride,1-(8-quinolyl)-2-phenylbenzindenylchromium(III) dichloride,1-(8-(2-methylquinolyl))-2-methyl-3-phenylcyclopentadienylchromium(III)dichloride, 1-(8-(2-methylquinolyl))-2-phenylindenylchromium(III)dichloride, 1-(2-pyridylmethyl)-3-phenylcyclopentadienylchromium(III)dichloride,1-(2-pyridylmethyl)-2-methyl-3-phenylcyclopentadienylchromium(III)dichloride, 1-(2-quinolylmethyl)-3-phenylcyclopentadienylchromiumdichloride, 1-(2-pyridylethyl)-3-phenylcyclopentadienylchromiumdichloride, 1-(2-pyridyl-1-methylethyl)-3-phenylcyclopentadienylchromiumdichloride,1-(2-pyridyl-1-phenylmethyl)-3-phenylcyclopentadienylchromiumdichloride, 1-(2-pyridylmethyl)-indenylchromium(III) dichloride,1-(2-quinolylmethyl)indenylchromium dichloride,1-(2-pyridylethyl)indenylchromium dichloride,1-(2-pyridyl-1-methylethyl)indenylchromium dichloride,1-(2-pyridyl-1-phenylmethyl)indenylchromium dichloride,5-[(2-pyridyl)methyl]-1,2,3,4-tetramethylcyclopentadienylchromiumdichloride and 1-(8-(2-methylquinolyl))-2-methylbenzindenylchromium(III)dichloride.

The preparation of such functional cyclopentadienyl ligands is known.Various synthetic routes to these complexing ligands are described by,for example, M. Enders et al., in Chem. Ber. (1996), 129, 459-463 or P.Jutzi and U. Siemeling in J. Orgmet. Chem. (1995), 500, 175-185.

The synthesis of such complexes can be carried out by methods known perse, with the reaction of the appropriately substituted, cyclichydrocarbon anions with halides of titanium, vanadium or chromium beingpreferred. Examples of appropriate preparative methods are described,for example, in Journal of Organometallic Chemistry, 369 (1989), 359-370and in EP-A-1212333.

Particularly suitable hafnocenes (A2) are hafnium complexes of thegeneral formula (VI)

where the substituents and indices have the following meanings:

-   -   X^(B) is fluorine, chlorine, bromine, iodine, hydrogen,        C₁-C₁₀-alkyl, C₂-C₁₀-alkenyl, C₆-C₁₅-aryl, alkylaryl having from        1 to 10 carbon atoms in the alkyl part and from 6 to 20 carbon        atoms in the aryl part, —OR^(6B) or —NR^(6B)R^(7B), or two        radicals X^(B) form a substituted or unsubstituted diene ligand,        in particular a 1,3-diene ligand, and the radicals X^(B) are        identical or different and may be joined to one another,    -   E^(1B)-E^(5B) are each carbon or not more than one E^(1B) to        E^(5B) is phosphorus or nitrogen, preferably carbon,    -   t is 1, 2 or 3 and is, depending on the valence of Hf, such that        the metallocene complex of the general formula (VI) is        uncharged,

where

-   -   R^(6B) and R^(7B) are each C₁-C₁₀-alkyl, C₆-C₁₅-aryl, alkylaryl,        arylalkyl, fluoroalkyl or fluoroaryl each having from 1 to 10        carbon atoms in the alkyl part and from 6 to 20 carbon atoms in        the aryl part and    -   R^(1B) to R^(5B) are each, independently of one another        hydrogen, C₁-C₂₂-alkyl, 5- to 7-membered cycloalkyl or        cycloalkenyl which may in turn bear C₁-C₁₀-alkyl groups as        substituents, C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, arylalkyl having from        1 to 16 carbon atoms in the alkyl part and from 6 to 21 carbon        atoms in the aryl part, NR^(8B) ₂, N(SiR^(8B) ₃)₂, OR^(8B),        OSiR^(8B) ₃, SiR^(8B) ₃, where the organic radicals        R^(1B)-R^(5B) may also be substituted by halogens and/or two        radicals R^(1B)-R^(5B), in particular vicinal radicals, may also        be joined to form a five-, six- or seven-membered ring, and/or        two vicinal radicals R^(1D)-R^(5D) may be joined to form a        five-, six- or seven-membered heterocycle containing at least        one atom from the group consisting of N, P, O and S, where    -   the radicals R^(8B) can be identical or different and can each        be C₁-C₁₀-alkyl, C₃-C₁₀-cycloalkyl, C₆-C₁₅-aryl, C₁-C₄-alkoxy or        C₆-C₁₀-aryloxy and    -   Z^(1B) is X^(B) or

where the radicals

-   -   R^(9B) to R^(13B) are each, independently of one another,        hydrogen, C₁-C₂₂-alkyl, 5- to 7-membered cycloalkyl or        cycloalkenyl which may in turn bear C₁-C₁₀-alkyl groups as        substituents, C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, arylalkyl having from        1 to 16 carbon atoms in the alkyl part and 6-21 carbon atoms in        the aryl part, NR^(14B) ₂, N(SiR^(14B) ₃)₂, OR^(14B), OSiR^(14B)        ₃, SiR^(14B) ₃, where the organic radicals R^(9B)-R^(13B) may        also be substituted by halogens and/or two radicals        R^(9B)-R^(13B), in particular vicinal radicals, may also be        joined to form a five-, six- or seven-membered ring, and/or two        vicinal radicals R^(9B)-R^(13B) may be joined to form a five-,        six- or seven-membered heterocycle containing at least one atom        from the group consisting of N, P, O and S, where    -   the radicals R^(14B) are identical or different and are each        C₁-C₁₀-alkyl, C₃-C₁₀-cycloalkyl, C₆-C₁₅-aryl, C₁-C₄-alkoxy or        C₆-C₁₀-aryloxy,    -   E^(6B)-E^(10B) are each carbon or not more than one E^(6B) to        E^(10B) is phosphorus or nitrogen, preferably carbon,

or where the radicals R^(4B) and Z^(1B) together form an —R^(15B)_(v)—A^(1B)— group, where

-   -   R^(15B) is

where

-   -   R^(16B)-R^(21B) are identical or different and are each a        hydrogen atom, a halogen atom, a trimethylsilyl group, a        C₁-C₁₀-alkyl group, a C₁-C₁₀-fluoroalkyl group, a        C₆-C₁₀-fluoroaryl group, a C₆-C₁₀-aryl group, a C₁-C₁₀-alkoxy        group, a C₇-C₁₅-alkylaryloxy group, a C₂-C₁₀-alkenyl group, a        C₇-C₄₀-arylalkyl group, a C₈-C₄₀-arylalkenyl group or a        C₇-C₄₀-alkylaryl group or two adjacent radicals together with        the atoms connecting them form a saturated or unsaturated ring        having from 4 to 15 carbon atoms, and    -   M^(2B)-M^(4B) are each silicon, germanium or tin, or preferably        silicon,    -   A^(1B) is

-   -   —NR^(22B) ₂, —PR^(22B) ₂ or an unsubstituted, substituted or        fused, heterocyclic ring system, where    -   the radicals R^(22B) are each, independently of one another,        C₁-C₁₀-alkyl, C₆-C₁₅-aryl, C₃-C₁₀-cycloalkyl, C₇-C₁₈-alkylaryl        or Si(R^(23B))₃,    -   R^(23B) is hydrogen, C₁-C₁₀-alkyl, C₆-C₁₅-aryl which may in turn        bear C₁-C₄-alkyl groups as substituents or C₃-C₁₀-cycloalkyl,    -   v is 1 or when A^(1B) is an unsubstituted, substituted or fused,        heterocyclic ring system may also be 0

or where the radicals R^(4B) and R^(12B) together form an —R^(15B)—group.

A^(1B) can, for example together with the bridge R^(15B), form an amine,ether, thioether or phosphine. However, A^(1B) can also be anunsubstituted, substituted or fused, heterocyclic aromatic ring systemwhich can contain heteroatoms from the group consisting of oxygen,sulfur, nitrogen and phosphorus in addition to ring carbons. Examples of5-membered heteroaryl groups which can contain from one to four nitrogenatoms and/or a sulfur or oxygen atom as ring members in addition tocarbon atoms are 2-furyl, 2-thienyl, 2-pyrrolyl, 3-isoxazolyl,5-isoxazolyl, 3-isothiazolyl, 5-isothiazolyl, 1-pyrazolyl, 3-pyrazolyl,5-pyrazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-thiazolyl,4-thiazolyl, 5-thiazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl,1,2,4-oxadiazol-3-yl, 1,2,4-oxa-diazol-5-yl, 1,3,4-oxadiazol-2-yl and1,2,4-triazol-3-yl. Examples of 6-membered heteroaryl groups which maycontain from one to four nitrogen atoms and/or a phosphorus atom are2-pyridinyl, 2-phosphabenzenyl, 3-pyridazinyl, 2-pyrimidinyl,4-pyrimidinyl, 2-pyrazinyl, 1,3,5-triazin-2-yl and 1,2,4-triazin-3-yl,1,2,4-triazin-5-yl and 1,2,4-triazin-6-yl. The 5-membered and 6-memberedheteroaryl groups may also be substituted by C₁-C₁₀-alkyl, C₆-C₁₀-aryl,alkylaryl having from 1 to 10 carbon atoms in the alkyl part and 6-10carbon atoms in the aryl part, trialkylsilyl or halogens such asfluorine, chlorine or bromine or be fused with one or more aromatics orheteroaromatics. Examples of benzo-fused 5-membered heteroaryl groupsare 2-indolyl, 7-indolyl, 2-coumaronyl, 7-coumaronyl, 2-thionaphthenyl,7-thionaphthenyl, 3-indazolyl, 7-indazolyl, 2-benzimidazolyl and7-benzimidazolyl. Examples of benzo-fused 6-membered heteroaryl groupsare 2-quinolyl, 8-quinolyl, 3-cinnolyl, 8-cinnolyl, 1-phthalazyl,2-quinazolyl, 4-quinazolyl, 8-quinazolyl, 5-quinoxalyl, 4-acridyl,1-phenanthridyl and 1-phenazyl. Naming and numbering of the heterocycleshas been taken from L. Fieser and M. Fieser, Lehrbuch der organischenChemie, 3^(rd) revised edition, Verlag Chemie, Weinheim 1957.

The radicals X^(B) in the general formula (XIV) are preferablyidentical, preferably fluorine, chlorine, bromine, C₁-C₇-alkyl oraralkyl, in particular chlorine, methyl or benzyl.

The synthesis of such complexes can be carried out by methods known perse, with the reaction of the appropriately substituted cyclichydrocarbon anions with halides of hafnium being preferred. Examples ofappropriate preparative methods are described, for example, in Journalof Organometallic Chemistry, 369 (1989), 359-370.

The hafnocenes can be used in the Rac or pseudo-Rac form. The termpseudo-Rac refers to complexes in which the two cyclopentadienyl ligandsare in the Rac arrangement relative to one another when all othersubstituents of the complex are disregarded.

Examples of suitable hafnocenes (A2) are, inter alia,methylenebis(cyclopentadienyl)hafnium dichloride,methylenebis(3-methylcyclopentadienyl)-hafnium dichloride,methylenebis(3-n-butylcyclopentadienyl)hafnium dichloride,methylenebis(indenyl)hafnium dichloride, methylenebis(tetrahydroindenyl)hafnium dichloride, isopropylidenebis(cyclopentadienyl)hafniumdichloride, isopropylidenebis(3-trimethylsilylcyclopentadienyl)hafniumdichloride, isopropylidenebis(3-methylcyclopentadienyl)hafniumdichloride, isopropylidenebis(3-n-butylcyclopentadienyl)hafniumdichloride, isopropylidenebis(3-phenylcyclopentadienyl)hafniumdichloride, isopropylidenebis(indenyl)hafnium dichloride,isopropylidenebis(tetrahydroindenyl)hafnium dichloride,dimethylsilanediylbis(cyclopentadienyl)hafnium dichloride,dimethylsilanediylbis(indenyl)hafnium dichloride,dimethylsilanediylbis(tetrahydroindenyl)hafnium dichloride,ethylenebis(cyclopentadienyl)hafnium dichloride,ethylenebis(indenyl)hafnium dichloride,ethylenebis(tetrahydroindenyl)hafnium dichloride,tetramethylethylene-9-fluorenyl-cyclopentadienylhafnium dichloride,dimethylsilanediylbis(tetramethylcyclopentadienyl)hafnium dichloride,dimethylsilanediylbis(3-trimethylsilylcyclopentadienyl)hafniumdichloride, dimethylsilanediylbis(3-methylcyclopentadienyl)hafniumdichloride, dimethylsilanediylbis(3-n-butylcyclopentadienyl)hafniumdichloride,dimethylsilanediylbis(3-tert-butyl-5-methylcyclopentadienyl)hafniumdichloride,dimethylsilanediylbis(3-tert-butyl-5-ethylcyclopentadienyl)hafniumdichloride, dimethylsilanediylbis(2-methylindenyl)hafnium dichloride,dimethylsilanediylbis(2-isopropylindenyl)hafnium dichloride,dimethylsilanediylbis(2-tert-butylindenyl)hafnium dichloride,diethylsilanediylbis(2-methylindenyl)hafnium dibromide,dimethylsilanediylbis(3-methyl-5-methylcyclopentadienyl)hafniumdichloride,dimethylsilanediylbis(3-ethyl-5-isopropylcyclopentadienyl)hafniumdichloride, dimethylsilanediylbis(2-ethylindenyl)hafnium dichloride,dimethylsilanediylbis(2-methyl-4,5-benzindenyl)hafnium dichloride,dimethylsilanediylbis(2-ethyl-4,5-benzindenyl)hafnium dichloride,methylphenylsilanediylbis(2-methyl-4,5-benzindenyl)hafnium dichloride,methylphenylsilanediylbis(2-ethyl-4,5-benzindenyl)hafnium dichloride,diphenylsilanediylbis(2-methyl-4,5-benzindenyl)hafnium dichloride,diphenylsilanediylbis(2-ethyl-4,5-benzindenyl)hafnium dichloride,diphenylsilanediylbis(2-methylindenyl)hafnium dichloride,dimethylsilanediylbis(2-methyl-4-phenylindenyl)hafnium dichloride,dimethylsilanediylbis(2-ethyl-4-phenylindenyl)hafnium dichloride,dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)hafnium dichloride,dimethylsilanediylbis(2-ethyl-4-(1-naphthyl)indenyl)hafnium dichloride,dimethylsilanediylbis(2-propyl-4-(1-naphthyl)indenyl)hafnium dichloride,dimethylsilanediylbis(2-i-butyl-4-(1-naphthyl)indenyl)hafniumdichloride,dimethylsilanediylbis(2-propyl-4-(9-phenanthryl)indenyl)hafniumdichloride, dimethylsilanediylbis(2-methyl-4-isopropylindenyl)hafniumdichloride,dimethylsilanediylbis(2,7-dimethyl-4-isopropylindenyl)hafniumdichloride,dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)-hafniumdichloride,dimethylsilanediylbis(2-methyl-4[p-trifluoromethylphenyl]indenyl)hafniumdichloride,dimethylsilanediylbis(2-methyl-4-[3′,5′-dimethylphenyl]indenyl)hafniumdichloride, dimethylsilanediylbis(2-methyl-4-[4′-tert-butylphenyl]indenyl)hafnium dichloride,diethylsilanediylbis(2-methyl-4-[4′-tert-butylphenyl]indenyl)hafniumdichloride,dimethylsilanediylbis(2-ethyl-4-[4′-tert-butylphenyl]indenyl)hafniumdichloride,dimethylsilanediylbis(2-propyl-4-[4′-tert-butyl-phenyl]indenyl)hafniumdichloride,dimethylsilanediylbis(2-isopropyl-4-[4′-tert-butylphenyl]-indenyl)hafniumdichloride,dimethylsilanediyl(2-isopropyl-4-phenylindenyl)(2-methyl-4-phenyl-indenyl)hafniumdichloride,dimethylsilanediyl(2-isopropyl-4-(1-naphthyl)indenyl)(2-methyl-4-(1-naphthyl)indenyl)hafniumdichloride, dimethylsilanediyl(2-isopropyl-4-[4′-tert-butylphenyl)indenyl)(2-methyl-4-[4′-tert-butylphenyl]indenyl)hafniumdichloride,dimethylsilanediyl(2-isopropyl-4-[4′-tert-butylphenyl]indenyl)(2-methyl-4-[1′-naphthyl]indenyl)hafniumdichloride andethylene(2-isopropyl-[4-4′-tert-butylphenyl]indenyl)(2-methyl-44′-tert-butylphenyl]indenyl)hafniumdichloride, and also the correspondding dimethylhafnium,monochloromono(alkylaryloxy)hafnium and di(alkylaryloxy)hafniumcompounds. The complexes can be used in the rac form, the meso form oras mixtures of these.

Among the hafnocenes of the general formula (VI), those of the formula(VII)

are preferred.

Among the compounds of the formula (VII), preference is given to thosein which

-   -   X^(B) is fluorine, chlorine, bromine, C₁-C₄-alkyl or benzyl, or        two radicals X^(B) form a substituted or unsubstituted butadiene        ligand,    -   t is 1 or 2, preferably 2,    -   R^(1B) to R^(5B) are each hydrogen, C₁-C₈-alkyl, C₆-C₈-aryl,        NR^(8B) ₂, OSiR^(8B) ₃ or Si(R^(8B))₃ and    -   R^(9B) to R^(13B) are each hydrogen, C₁-C₈-alkyl or C₆-C₈-aryl,        NR^(14B) ₂, OSiR^(14B) ₃ or Si(R^(14B))₃

or in each case two radicals R^(1B) to R^(5B) and/or R^(9B) to R^(13B)together with the C₅ ring form an indenyl, fluorenyl or substitutedindenyl or fluorenyl system.

The hafnocenes of the formula (VII) in which the cyclopentadienylradicals are identical are particularly useful.

Examples of particularly suitable compounds D) of the formula (VII) are,inter alia: bis(cyclopentadienyl)hafnium dichloride, bis(indenyl)hafniumdichloride, bis(fluorenyl)hafnium dichloride,bis(tetrahydroindenyl)hafnium dichloride,bis(pentamethylcyclopentadienyl)hafnium dichloride,bis(trimethylsilylcyclopentadienyl)hafnium dichloride,bis(trimethoxysilylcyclopentadienyl)hafnium dichloride,bis(ethylcyclopentadienyl)hafnium dichloride,bis(isobutylcyclopentadienyl)hafnium dichloride,bis(3-butenylcyclopentadienyl)hafnium dichloride,bis(methylcyclopentadienyl)hafnium dichloride,bis(1,3-di-tert-butylcyclopentadienyl)hafnium dichloride,bis(trifluoromethylcyclopentadienyl)hafnium dichloride,bis(tert-butylcyclopentadienyl)hafnium dichloride,bis(n-butylcyclopentadienyl)hafnium dichloride,bis(phenylcyclopentadienyl)hafnium dichloride,bis(N,N-dimethylaminomethylcyclopentadienyl)hafnium dichloride,bis(1,3-dimethylcyclopentadienyl)hafnium dichloride,bis(1-n-butyl-3-methylcyclopentadienyl)hafnium dichloride,(cyclopentadienyl)(methylcyclopentadienyl)hafnium dichloride,(cyclopentadienyl)(n-butylcyclopentadienyl)hafnium dichloride,(methylcyclopentadienyl)(n-butylcyclopentadienyl)hafnium dichloride,(cyclopentadienyl)(1-methyl-3-n-butylcyclopentadienyl)hafniumdichloride, bis(tetramethylcyclopentadienyl)hafnium dichloride and alsothe corresponding dimethylhafnium compounds. Further examples are thecorresponding hafnocene compounds in which one or two of the chlorideligands have been replaced by bromide or iodide.

Suitable catalysts B) are transition metal complexes with at least oneligand of the general formulae XV to XIX,

where the variables have the following meanings:

-   -   E^(1C) is nitrogen or phosphorus, in particular nitrogen,    -   E^(2C)-E^(4C) are each, independently of one another, carbon,        nitrogen or phosphorus, in particular carbon,    -   R^(1C)-R^(3C)are each, independently of one another, hydrogen        C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, alkylaryl having from        1 to 10 carbon atoms in the alkyl part and 6-20 carbon atoms in        the aryl part, halogen, NR^(18C) ₂, OR^(18C), SiR^(19C) ₃, where        the organic radicals R^(1C)-R^(3C) may also be substituted by        halogens and/or two vicinal radicals R^(1C)-R^(3C) may also be        joined to form a five-, six- or seven-membered ring, and/or two        vicinal radicals R^(1C)-R^(3C) are joined to form a five-, six-        or seven-membered heterocycle containing at least one atom from        the group consisting of N, P, O and S,    -   R^(4C)-R^(7C) are each, independently of one another, hydrogen,        C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, alkylaryl having from        1 to 10 carbon atoms in the alkyl part and 6-20 carbon atoms in        the aryl part, NR^(18C) ₂, SiR^(19C) ₃, where the organic        radicals R^(4C)-R^(7C) may also be substituted by halogens        and/or two geminal or vicinal radicals R^(4C)-R^(7C) may also be        joined to form a five-, six- or seven-membered ring, and/or two        geminal or vicinal radicals R^(4C)-R^(9C) are joined to form a        five-, six- or seven-membered heterocycle containing at least        one atom from the group consisting of N, P, O and S, and when v        is 0, R^(6C) is a bond to L^(1C) and/or R^(7C) is a bond to        L^(2C) so that L^(1C) forms a double bond to the carbon atom        bearing R^(4C) and/or L^(2C) forms a double bond to the carbon        atom bearing R^(5C),    -   u is 0 when E^(2C)-E^(4C) is nitrogen or phosphorus and is 1        when E^(2C)-E^(4C) is carbon,    -   L^(1C)-L^(2C) are each, independently of one another, nitrogen        or phosphorus, in particular nitrogen,    -   R^(8C)-R^(11C) are each, independently of one another,        C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, alkylaryl having from        1 to 10 carbon atoms in the alkyl part and 6-20 carbon atoms in        the aryl part, halogen, NR^(18C) ₂, OR^(18C), SiR^(19C) ₃, where        the organic radicals R^(8C)-R^(11C) may also be substituted by        halogens and/or two vicinal radicals R^(8C)-R^(17C) may also be        joined to form a five-, six- or seven-membered ring, and/or two        vicinal radicals R^(8C)-R^(17C) are joined to form a five-, six-        or seven-membered heterocycle containing at least one atom from        the group consisting of N, P, O and S,    -   R^(12C)-R^(17C) are each, independently of one another,        hydrogen, C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part, halogen, NR^(18C) ₂, OR^(18C),        SiR^(19C) ₃, where the organic radicals R^(12C)-R^(17C) may also        be substituted by halogens and/or two vicinal radicals        R^(8C)-R^(17C) may also be joined to form a five-, six- or        seven-membered ring, and/or two vicinal radicals R^(8C)-R^(17C)        are joined to form a five-, six- or seven-membered heterocycle        containing at least one atom from the group consisting of N, P,        O and S,    -   the indices v are each, independently of one another, 0 or 1,    -   the radicals X^(C) are each, independently of one another,        fluorine, chlorine, bromine, iodine, hydrogen, C₁-C₁₀-alkyl,        C₂-C₁₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1-10 carbon atoms        in the alkyl part and 6-20 carbon atoms in the aryl part,        NR^(18C) ₂, OR^(18C), SR^(18C), SO₃R^(18C), OC(O)R^(18C), CN,        SCN, β-diketonate, CO, BF₄ ⁻, PF₆ ⁻ or a bulky noncoordinating        anion and the radicals X^(C) may be joined to one another,    -   the radicals R^(18C) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part, SiR^(19C) ₃, where the organic        radicals R^(18C) may also be substituted by halogens or        nitrogen- and oxygen-containing groups and two radicals R^(18C)        may also be joined to form a five- or six-membered ring,    -   the radicals R^(19C) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part, where the organic radicals        R^(19C) may also be substituted by halogens or nitrogen- and        oxygen-containing groups and two radicals R^(19C) may also be        joined to form a five- or six-membered ring,    -   s is 1, 2, 3 or 4, in particular 2 or 3,    -   D is an uncharged donor and    -   t is from 0 to 4, in particular 0, 1 or 2.

The three atoms E^(2C) to E^(4C) in a molecule can be identical ordifferent. If E^(1C) is phosphorus, then E^(2C) to E^(4C) are preferablyeach carbon. If E^(1C) is nitrogen, then E^(2C) to E^(4C) are eachpreferably nitrogen or carbon, in particular carbon.

The substituents R^(1C)-R^(3C) and R^(8C)-R^(17C) can be varied within awide range. Possible carboorganic substituents R^(1C)-R^(3C) andR^(8C)-R^(17C) are, for example, the following: C₁-C₂₂-alkyl which maybe linear or branched, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl,n-decyl or n-dodecyl, 5- to 7-membered cycloalkyl which may in turn beara C₁-C₁₀-alkyl group and/or C₆-C₁₀-aryl group as substituents, e.g.cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl, cyclononyl or cyclododecyl, C₂-C₂₂-alkenyl which may belinear, cyclic or branched and in which the double bond may be internalor terminal, e.g. vinyl, 1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl,hexenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl or cyclooctadienyl,C₆-C₂₂-aryl which may be substituted by further alkyl groups, e.g.phenyl, naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl, 2,3-,2,4-, 2,5- or 2,6-dimethylphenyl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6-or 3,4,5-trimethylphenyl, or arylalkyl which may be substituted byfurther alkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or2-ethylphenyl, where two radicals R^(1C) to R^(3C) and/or two vicinalradicals R^(8C)-R^(17C) may also be joined to form a 5-, 6- or7-membered ring and/or two of the vicinal radicals R^(1C)-R^(3C) and/ortwo of the vicinal radicals R^(8C)-R^(17C) may be joined to form afive-, six- or seven-membered heterocycle containing at least one atomfrom the group consisting of N, P, O and S and/or the organic radicalsR^(1C)-R^(3C) and/or R^(8C)-R^(17C) may also be substituted by halogenssuch as fluorine, chlorine or bromine. Furthermore, R^(1C)-R^(3C) andR^(8C)-R^(17C) can also be amino NR^(18C) ₂ or N(SiR^(19C) ₃)₂, alkoxyor aryloxy OR^(18C), for example dimethylamino, N-pyrrolidinyl,picolinyl, methoxy, ethoxy or isopropoxy or halogen such as fluorine,chlorine or bromine. Possible radicals R^(19C) in organosiliconsubstituents SiR^(19C) ₃ are the same carboorganic radicals as have beendescribed above for R^(1C)-R^(3C), where two R^(19C) may also be joinedto form a 5- or 6-membered ring, e.g. trimethylsilyl, triethylsilyl,butyldimethylsilyl, tributylsilyl, tri-tert-butysilyl, triallylsilyl,triphenylsilyl or dimethylphenylsilyl. These SiR^(19C) ₃ radicals mayalso be bound to E^(2C)-E^(4C) via an oxygen or nitrogen, for exampletrimethylsilyloxy, triethylsilyloxy, butyldimethylsilyloxy,tributylsilyloxy or tri-tert-butylsilyloxy.

Preferred radicals R^(1C)-R^(3C) are hydrogen, methyl, trifluoromethyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl,n-hexyl, n-heptyl, n-octyl, vinyl, allyl, benzyl, phenyl, orthodialkyl-or -dichloro-substituted phenyls, trialkyl- or trichloro-substitutedphenyls, naphthyl, biphenyl and anthranyl. Particularly preferredorganosilicon substituents are trialkylsilyl groups having from 1 to 10carbon atoms in the alkyl radical, in particular trimethylsilyl groups.

Preferred radicals R^(12C)-R^(17C) are hydrogen, methyl,trifluoromethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, vinyl, allyl, benzyl,phenyl, fluorine, chlorine and bromine, in particular hydrogen. Inparticular, R^(13C) and R^(16C) are each methyl, trifluoromethyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl,n-heptyl, n-octyl, vinyl, allyl, benzyl, phenyl, fluorine, chlorine orbromine and R^(12C), R^(14C), R^(15C) and R^(17C) are each hydrogen.

Preferred radicals R^(8C)-R^(11C) are methyl, trifluoromethyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl,n-heptyl, n-octyl, vinyl, allyl, benzyl, phenyl, fluorine, chlorine andbromine. In particular, R^(8C) and R^(10C) are each a C₁-C₂₂-alkyl whichmay also be substituted by halogens, in particular a C₁-C₂₂-n-alkylwhich may also be substituted by halogens, e.g. methyl, trifluoromethyl,ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, vinyl,or a halogen such as fluorine, chlorine or bromine and R^(9C) andR^(11C) are each a halogen such as fluorine, chlorine or bromine.Particular preference is given to R^(8C) and R^(10C) each being aC₁-C₂₂-alkyl which may also be substituted by halogens, in particular aC₁-C₂₂-n-alkyl which may also be substituted by halogens, e.g. methyl,trifluoromethyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl,n-octyl, vinyl and R^(9C) and R^(11C) are each a halogen such asfluorine, chlorine or bromine.

In particular, R^(12C), R^(14C), R^(15C) and R^(17C) are identical,R^(13C) and R^(16C) are identical, R^(9C) and R^(11C) are identical andR^(8C) and R^(10C) are identical. This is also preferred in thepreferred embodiments described above.

The substituents R^(4C)-R^(7C), too, can be varied within a wide range.Possible carboorganic substituents R^(4C)-R^(7C) are, for example, thefollowing: C₁-C₂₂-alkyl which may be linear or branched, e.g. methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl,n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, 5- to7-membered cycloalkyl which may in turn bear a C₁-C₁₀-alkyl group and/orC₆-C₁₀-aryl group as substituent, e.g. cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl orcyclododecyl, C₂-C₂₂-alkenyl which may be linear, cyclic or branched andin which the double bond may be internal or terminal, e.g. vinyl,1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl,cyclohexenyl, cyclooctenyl or cyclooctadienyl, C₆-C₂₂-aryl which may besubstituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl,anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5- or2,6-dimethylphenyl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or3,4,5-trimethylphenyl, or arylalkyl, where the arylalkyl may besubstituted by further alkyl groups, e.g. benzyl, o-, m-,p-methylbenzyl, 1- or 2-ethylphenyl, where two radicals R^(4C) to R^(7C)may also be joined to form a 5-, 6- or 7-membered ring and/or twogeminal radicals R^(4C)-R^(7C) may be joined to form a five-, six- orseven-membered heterocycle containing at least one atom from the groupconsisting of N, P, O and S and/or the organic radicals R^(4C)-R^(7C)may also be substituted by halogens such as fluorine, chlorine orbromine. Furthermore, R^(4C)-R^(7C) may be amino NR^(18C) ₂ orN(SiR^(19C) ₃)₂, for example dimethylamino, N-pyrrolidinyl or picolinyl.Possible radicals R^(19C) in organosilicone substituents SiR^(19C) ₃ arethe same carboorganic radicals as have been described above forR^(1C)-R^(3C), where two R^(19C) may also be joined to form a 5- or6-membered ring, e.g. trimethylsilyl, triethylsilyl, butyldimethylsilyl,tributylsilyl, tri-tert-butylsilyl, triallylsilyl, triphenylsilyl ordimethylphenylsilyl. These SiR^(19C) ₃ radicals can also be bound vianitrogen to the carbon bearing them. When v is 0, R^(6C) is a bond toL^(1C) and/or R^(7C) is a bond to L^(2C), so that L^(1C) forms a doublebond to the carbon atom bearing R^(4C) and/or L^(2C) forms a double bondto the carbon atom bearing R^(5C).

Preferred radicals R^(4C)-R^(7C) are hydrogen, methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl,n-octyl, benzyl, phenyl, ortho-dialkyl- or dichloro-substituted phenyls,trialkyl- or trichloro-substituted phenyls, naphthyl, biphenyl andanthranyl. Preference is also given to amide substituents NR^(18C) ₂, inparticular secondary amides such as dimethylamide, N-ethylmethylamide,diethylamide, N-methylpropylamide, N-methylisopropylamide,N-ethylisopropylamide, dipropylamide, diisopropylamide,N-methylbutylamide, N-ethylbutylamide, N-methyl-tert-butylamide,N-tert-butylisopropylamide, dibutylamide, di-sec-butylamide,diisobutylamide, tert-amyl-tert-butylamide, dipentylamide,N-methylhexylamide, dihexylamide, tert-amyl-tert-octylamide,dioctylamide, bis(2-ethylhexyl)amide, didecylamide,N-methyloctadecylamide, N-methylcyclohexylamide, N-ethylcyclohexylamide,N-isopropylcyclohexylamide, N-tert-butylcyclohexylamide,dicyclohexylamide, pyrrolidine, piperidine, hexamethylenimine,decahydroquinoline, diphenylamine, N-methylanilide or N-ethylanilide.

L^(1C) and L^(2C) are each, independently of one another, nitrogen orphosphorus, in particular nitrogen, and when v is 0 can form a doublebond with the carbon atom bearing R^(4C) or R^(5C). In particular, whenv is 0, L^(1C) and/or L^(2C) together with the carbon atom bearingR^(4C) or R^(5C) form an imino group —CR^(4C)═N— or —CR^(5C)═N—. When vis 1, L^(1C) and/or L^(2C) together with the carbon atom bearing R^(4C)or R^(5C) forms, in particular, an amido group —CR^(4C)R^(6C)-N⁻— or—CR^(5C)R^(7C)-N⁻—.

The ligands X^(C) result, for example, from the choice of theappropriate starting metal compounds used for the synthesis of the ironcomplexes, but can also be varied afterward. Possible ligands X^(C) are,in particular, the halogens such as fluorine, chlorine, bromine oriodine, in particular chlorine. Alkyl radicals such as methyl, ethyl,propyl, butyl, vinyl, allyl, phenyl or benzyl are also usable ligandsX^(C). As further ligands X^(C), mention may be made, purely by way ofexample and in no way exhaustively, of trifluoroacetate, BF₄ ⁻, PF₆ ⁻and weakly coordinating or noncoordinating anions (cf., for example, S.Strauss in Chem. Rev. 1993, 93, 927-942), e.g. B(C₆F₅)₄ ⁻. Amides,alkoxides, sulfonates, carboxylates and β-diketonates are alsoparticularly useful ligands X^(C). Some of these substituted ligands Xare particularly preferably used since they are obtainable from cheapand readily available starting materials. Thus, a particularly preferredembodiment is that in which X^(C) is dimethylamide, methoxide, ethoxide,isopropoxide, phenoxide, naphthoxide, triflate, p-toluenesulfonate,acetate or acetylacetonate.

Variation of the radicals R^(18C) enables, for example, physicalproperties such as solubility to be finely adjusted. Possiblecarboorganic substituents R^(18C) are, for example, the following:C₁-C₂₀-alkyl which may be linear or branched, e.g. methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl,n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, 5- to 7-memberedcycloalkyl which may in turn bear a C₆-C₁₀-aryl group as substituent,e.g. cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl, cyclononyl or cyclododecyl, C₂-C₂₀-alkenyl which may belinear, cyclic or branched and in which the double bond may be internalor terminal, e.g. vinyl, 1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl,hexenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl or cyclooctadienyl,C₆-C₂₀-aryl which may be substituted by further alkyl groups and/or N-or O-containing radicals, e.g. phenyl, naphthyl, biphenyl, anthranyl,o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5- or 2,6-dimethylphenyl, 2,3,4-,2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or 3,4,5-trimethylphenyl,2-methoxyphenyl, 2-N,N-dimethylaminophenyl, or arylalkyl which may besubstituted by further alkyl groups, e.g. benzyl, o-, m-,p-methylbenzyl, 1- or 2-ethylphenyl, where two radicals R^(18C) may alsobe joined to form a 5- or 6-membered ring and the organic radicalsR^(18C) may also be substituted by halogens such as fluorine, chlorineor bromine. Possible radicals R^(19C) in organosilicon substituentsSiR^(19C) ₃ are the same radicals which have been described above forR^(18C), where two radicals R^(19C) may also be joined to form a 5- or6-membered ring, e.g. trimethylsilyl, triethylsilyl, butyldimethylsilyl,tributylsilyl, triallylsilyl, triphenylsilyl or dimethylphenylsilyl.Preference is given to using C₁-C₁₀-alkyl such as methyl, ethyl,n-propyl, n-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, andalso vinyl allyl, benzyl and phenyl as radicals R^(18C).

The number s of the ligands X^(C) depends on the oxidation state of theiron. The number s can thus not be given in general terms. The oxidationstate of the iron in catalytically active complexes is usually known tothose skilled in the art. However, it is also possible to use complexeswhose oxidation state does not correspond to that of the activecatalyst. Such complexes can then be appropriately reduced or oxidizedby means of suitable activators. Preference is given to using ironcomplexes in the oxidation state +3 or +2.

D is an uncharged donor, in particular an uncharged Lewis base or Lewisacid, for example amines, alcohols, ethers, ketones, aldehydes, esters,sulfides or phosphines which may be bound to the iron center or elsestill be present as residual solvent from the preparation of the ironcomplexes.

The number t of the ligands D can be from 0 to 4 and is often dependenton the solvent in which the iron complex is prepared and the time forwhich the resulting complexes are dried and can therefore also be anonintegral number such as 0.5 or 1.5. In particular, t is 0, 1 to 2.

In a preferred embodiment are

where

-   -   E^(2C)-E^(4C) are each, independently of one another, carbon,        nitrogen or phosphorus, in particular carbon,    -   R^(1C)-R^(3C)are each, independently of one another, hydrogen,        C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, C₆ ⁻C₂₂-aryl, alkylaryl having        from 1 to 10 carbon atoms in the alkyl part and 6-20 carbon        atoms in the aryl part, halogen, NR^(18C) ₂, OR^(18C) ₂,        SiR^(19C) ₃, where the organic radicals R^(1C)-R^(3C) may also        be substituted by halogens and/or two vicinal radicals        R^(1C)-R^(3C) may also be joined to form a five-, six- or        seven-membered ring, and/or two vicinal radicals R^(1C)-R^(3C)        are bound to form a five-, six- or seven-membered heterocycle        containing at least one atom from the group consisting of N, P,        O and S,    -   R^(4C)-R^(5C) are each independently of one another, hydrogen,        C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, alkylaryl having from        1 to 10 carbon atoms in the alkyl part and 6-20 carbon atoms in        the aryl part, NR^(18C) ₂, SiR^(19C) ₃, where the organic        radicals R^(4C)-R^(5C) may also be substituted by halogens,    -   u is 0 when E^(2C) -E^(4C) is nitrogen or phosphorus and is 1        when E^(2C)-E^(4C) is carbon,    -   L^(1C)-L^(2C) are each, independently of one another, nitrogen        or phosphorus, in particular nitrogen,    -   R^(8C)-R^(11C) are each, independently of one another,        C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, alkylaryl having from        1 to 10 carbon atoms in the alkyl part and 6-20 carbon atoms in        the aryl part, halogen, NR^(18C) ₂, OR^(18C), SiR^(19C) ₃, where        the organic radicals R^(8C)-R^(11C) may also be substituted by        halogens and/or two vicinal radicals R^(8C)-R^(17C) may also be        joined to form a five-, six- or seven-membered ring, and/or two        vicinal radicals R^(8C)-R^(17C) are joined to form a five-, six-        or seven-membered heterocycle containing at least one atom from        the group consisting of N, P, O and S,    -   R^(12C)-R^(17C) are each, independently of one another,        hydrogen, C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl, C₆-C₂₂-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part, halogen, NR^(18C) ₂, OR^(18C),        SiR^(19C) ₃, where the organic radicals R^(12C)-R^(17C) may also        be substituted by halogens and/or two vicinal radicals        R^(8C)-R^(17C) may also be joined to form a five-, six- or        seven-membered ring, and/or two vicinal radicals R^(8C)-R^(17C)        are joined to form a five-, six- or seven-membered heterocycle        containing at least one atom from the group consisting of N, P,        O or S,    -   the indices v are each, independently of one another, 0 or 1,    -   the radicals X^(C) are each, independently of one another,        fluorine, chlorine, bromine, iodine, hydrogen, C₁-C₁₀-alkyl,        C₂-C₁₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1-10 carbon atoms        in the alkyl part and 6-20 carbon atoms in the aryl part,        NR^(18C) ₂, OR^(18C), SR^(18C), SO₃R^(18C), OC(O)R^(18C), CN,        SCN, β-diketonate, CO, BF₄ ⁻, PF₆ ⁻ or a bulky noncoordinating        anion and the radicals X^(C) may be joined to one another,    -   the radicals R^(18C) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part, SiR^(19C) ₃, where the organic        radicals R^(18C) may also be substituted by halogens and        nitrogen- and oxygen-containing groups and two radicals R^(18C)        may also be joined to form a five- or six-membered ring,    -   the radicals R^(19C) are each, independently of one another,        hydrogen, C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl        having from 1 to 10 carbon atoms in the alkyl part and 6-20        carbon atoms in the aryl part, where the organic radicals        R^(19C) may also be substituted by halogens or nitrogen- and        oxygen-containing groups and two radicals R^(19C) may also be        joined to form a five- or six-membered ring,    -   s is 1, 2, 3 or 4, in particular 2 or 3,    -   D is an uncharged donor and    -   t is from 0 to 4, in particular 0, 1 or 2.

The embodiments and preferred embodiments described above likewise applyto E^(2C)-E^(4C), R^(1C)-R^(3C), X^(C), R^(18C) and R^(19C).

The substituents R^(4C)-R^(5C) can be varied within a wide range.Possible carboorganic substituents R^(4C)-R^(5C) are, for example, thefollowing: hydrogen, C₁-C₂₂-alkyl which may be linear or branched, e.g.methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl,n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, 5-to 7-membered cycloalkyl which may in turn bear a C₁-C₁₀-alkyl groupand/or C₆-C₁₀-aryl group as substituent, e.g. cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl orcyclododecyl, C₂-C₂₂-alkenyl which may be linear, cyclic or branched andin which the double bond may be internal or terminal, e.g. vinyl,1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl,cyclohexenyl, cyclooctenyl or cyclooctadienyl, C₆-C₂₂-aryl which may besubstituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl,anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5- or2,6-dimethylphenyl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or3,4,5-trimethylphenyl, or arylalkyl which may be substituted by furtheralkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or 2-ethylphenyl,where the organic radicals R^(4C)-R^(5C) may also be substituted byhalogens such as fluorine, chlorine or bromine. Furthermore,R^(4C)-R^(5C) can be amino NR^(18c) ₂ or N(SiR^(19C) ₃)₂, for exampledimethylamino, N-pyrrolidinyl or picolinyl. Possible radicals R^(19C) inorganosilicon substituents SiR^(19C) ₃ are the same carboorganicradicals as described above for R^(1C)-R^(3C), where two radicalsR^(19C) may also be joined to form a 5- or 6-membered ring, e.g.trimethylsilyl, triethylsilyl, butyldimethylsilyl, tributylsilyl,tritert-butylsilyl, triallylsilyl, triphenylsilyl ordimethylphenylsilyl. These SiR^(19C) ₃ radicals can also be bound vianitrogen to the carbon bearing them.

Preferred radicals R^(4C)-R^(5C) are hydrogen, methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl,n-octyl or benzyl, in particular methyl.

The substituents R^(8C)-R^(17C) can be varied within a wide range.Possible carboorganic substituents R^(8C)-R^(17C) are, for example, thefollowing: C₁-C₂₂-alkyl which may be linear or branched, e.g. methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl,n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, 5- to7-membered cycloalkyl which may in turn bear a C₁-C₁₀-alkyl group and/orC₆-C₁₀-aryl group as substituent, e.g. cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl orcyclododecyl, C₂-C₂₂-alkenyl which may be linear, cyclic or branched andin which the double may be internal or terminal, e.g. vinyl, 1-allyl,2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl,cyclohexenyl, cyclooctenyl or cyclooctadienyl, C₆-C₂₂-aryl which may besubstituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl,anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5- or2,6-dimethylphenyl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or3,4,5-trimethylphenyl, or arylalkyl which may be substituted by furtheralkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or 2-ethylphenyl,where two radicals R^(8C) to R^(17C) may also be joined to form a 5-, 6-or 7-membered ring and/or two of the vicinal radicals R^(8C)-R^(17C) maybe joined to form a five-, six- or seven-membered heterocycle containingat least one atom from the group consisting of N, P, O and S and/or theorganic radicals R^(8C)-R^(17C) may also be substituted by halogens suchas fluorine, chlorine or bromine. Furthermore, R^(8C)-R^(17C) can behalogen such as fluorine, chlorine, bromine, amino NR^(18C) ₂ orN(SiR^(19C) ₃)₂, alkoxy or aryloxy OR^(18C), for example dimethylamino,N-pyrrolidinyl, picolinyl, methoxy, ethoxy or isopropoxy. Possibleradicals R^(19C) in organosilicon substituents SiR^(19C) ₃ are the samecarboorganic radicals which have been mentioned above for R^(1C)-R^(3C),where two radicals R^(19C) may also be joined to form a 5- or 6-memberedring, e.g. trimethylsilyl, triethylsilyl, butyldimethylsilyl,tributylsilyl, tritertbutylsilyl, triallylsilyl, triphenylsilyl ordimethylphenylsilyl. These SiR^(19C) ₃ radicals can also be bound via anoxygen or nitrogen, for example trimethylsilyloxy, triethylsilyloxy,butyldimethylsilyloxy, tributylsilyloxy or tritert-butylsilyloxy.

Preferred radicals R^(12C)-R^(17C) are hydrogen, methyl,trifluoromethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, vinyl, allyl, benzyl,phenyl, fluorine, chlorine and bromine, in particular hydrogen. Inparticular, R^(13C) and R^(16C) are each methyl, trifluoromethyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl,n-heptyl, n-octyl, vinyl, allyl, benzyl, phenyl, fluorine, chlorine orbromine and R^(12C), R^(14C), R^(15C) and R^(17C) are each hydrogen.

Preferred radicals R^(8C)-R^(11C) are methyl, trifluoromethyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl,n-heptyl, n-octyl, vinyl, allyl, benzyl, phenyl, fluorine, chlorine andbromine. In particular R^(8C) and R^(10C) are each a C₁-C₂₂-alkyl whichmay also be substituted by halogens, in particular a C₁-C₂₂-n-alkylwhich may also be substituted by halogens, e.g. methyl, trifluoromethyl,ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, vinyl,or a halogen such as fluorine, chlorine or bromine and R^(9C) andR^(11C) are each a halogen such as fluorine, chlorine or bromine.Particular preference is given to R^(8C) and R^(10C) each being aC₁-C₂₂-alkyl which may also be substituted by halogens, in particular aC₁-C₂₂-n-alkyl which may also be substituted by halogens, e.g. methyl,trifluoromethyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl,n-octyl, vinyl and R^(9C) and R^(11C) each being a halogen such asfluorine, chlorine or bromine.

In particular, R^(12C), R^(14C), R^(15C) and R^(17C) are identical,R^(13C) and R^(16C) are identical, R^(9C) and R^(11C) are identical andR^(8C) and R^(10C) are identical. This is also preferred in thepreferred embodiments described above.

The preparation of the compounds B) is described, for example, in J. Am.Chem. Soc. 120, p. 4049 ff. (1998), J. Chem. Soc., Chem. Commun. 1998,849, and WO 98/27124. Preferred complexes B) are2,6-Bis[1-(2,6-dimethylphenylimino)ethyl]pyridine iron(II) dichloride,2,6-Bis[1-(2,4,6-trimethylphenylimino)ethyl]pyridine iron(II)dichloride, 2,6-Bis[1-(2-chloro-6-methylphenylimino)ethyl]pyridineiron(II) dichloride,2,6-Bis[1-(2,6-diisopropylphenylimino)ethyl]pyridine iron(II)dichloride, 2,6-Bis[1-(2,6-dichlorophenylimino)ethyl]pyridine iron(II)dichloride, 2,6-Bis[1-(2,6-diisopropyl phenylimino)methyl]pyridineiron(II) dichloride,2,6-Bis[1-(2,4-dichloro-6-methylphenylimino)ethyl]pyridine iron(II)dichloride, 2,6-Bis[1-(2,6-difluorophenylimino)ethyl]pyridine iron(II)dichloride, 2,6-Bis[1-(2,6-difbromophenylimino)ethyl]pyridine iron(II)dichloride or the respective dibromides or tribromides.

In the following, reference to a transition metal complex (A) orcatalyst (A) means a monocyclopentadienyl complex (A1) and/or ahafnocene (A2). The molar ratio of transition metal complex A) topolymerization catalyst B) is usually in the range from 1:100 to 100:1,preferably from 1:10 to 10:1 and particularly preferably from 1:5 to5:1. When a transition metal complex A) is used as sole catalyst underthe same reaction conditions in the homopolymerization orcopolymerization of ethylene, it preferably produces a higher Mw thandoes the complex (B) when it is used as sole complex under the samereaction conditions. The preferred embodiments of the complexes (A1),(A2) and (B) are likewise preferred in combinations of complex (A1) and(B) and in the combination of complex (A2) and (B).

The catalyst composition of the invention can be used alone or togetherwith further components as catalyst system for olefin polymerization.Furthermore, we have found catalyst systems for olefin polymerizationcomprising

-   -   A) at least one polymerization catalyst based on a        monocyclopentadienyl complex of a metal of groups 4-6 of the        Periodic Table of the Elements whose cyclopentadienyl system is        substituted by an uncharged donor (A1) or a hafnocene (A2),    -   B) at least one polymerization catalyst based on an iron        component having a tridentate ligand bearing at least two        ortho,ortho-disubstituted aryl radicals,    -   C) optionally one or more activating compounds,    -   D) optionally one or more organic or inorganic supports,    -   E) optionally one or more metal compounds of a metal of group 1,        2 or 13 of the Periodic Table.

In the following, reference to a transition metal complex (A) orcatalyst (A) means a monocyclopentadienyl complex (A1) and/or ahafnocene (A2). The molar ratio of transition metal complex A) topolymerization catalyst B) is usually in the range from 1:100 to 100:1,preferably from 1:10 to 10:1 and particularly preferably from 1:5 to5:1. When a transition metal complex A) is used as sole catalyst underthe same reaction conditions in the homopolymerization orcopolymerization of ethylene, it preferably produces a higher Mw thandoes the complex (B) when it is used as sole complex under the samereaction conditions. The preferred embodiments of the complexes (A1),(A2) and (B) are likewise preferred in combinations of complex (A1) and(B) and in the combination of complex (A2) and (B).

The monocyclopentadienyl complexes (A1), the hafnocene (A2) and/or theiron complex (B) sometimes have only a low polymerization activity andare then brought into contact with one or more activators, viz. thecomponent (C), in order to be able to display a good polymerizationactivity. The catalyst system therefore optionally further comprises, ascomponent (C) one or more activating compounds, preferably one or twoactivating compounds (C). The catalyst system of the inventionpreferably comprises one or more activators (C). Depending on thecatalyst combinations (A) and (B), one or more activating compounds (C)are advantageous. The activation of the transition metal complex (A) andof the iron complex (B) of the catalyst composition can be carried outusing the same activator or activator mixture or different activators.It is often advantageous to use the same activator (C) for both thecatalysts (A) and (B).

The activator or activators (C) can in each case be used in any amountsbased on the complexes (A) and (B) of the catalyst composition of theinvention. They are preferably used in an excess or in stoichiometricamounts, in each case based on the complex (A) or (B) which theyactivate. The amount of activating compound(s) to be used depends on thetype of the activator (C). In general, the molar ratio of transitionmetal complex (A) to activating compound (C) can be from 1:0.1 to1:10000, preferably from 1:1 to 1:2000. The molar ratio of iron complex(B) to activating compound (C) is also usually in the range from 1:0.1to 1:10000, preferably from 1:1 to 1:2000.

Suitable compounds (C) which are able to react with the transition metalcomplex (A) or the iron complex (B) to convert it into a catalyticallyactive or more active compound are, for example, compounds such as analuminoxane, a strong uncharged Lewis acid, an ionic compound having aLewis-acid cation or an ionic compound containing a Brönsted acid ascation.

As aluminoxanes, it is possible to use, for example, the compoundsdescribed in WO 00/31090. Particularly useful aluminoxanes areopen-chain or cyclic aluminoxane compounds of the general formula (X) or(XI)

where R^(1D)-R^(4D) are each, independently of one another, aC₁-C₆-alkyl group, preferably a methyl, ethyl, butyl or isobutyl groupand I is an integer from 1 to 40, preferably from 4 to 25.

A particularly useful aluminoxane compound is methylaluminoxane.

These oligomeric aluminoxane compounds are usually prepared bycontrolled reaction of a solution of a trialkylaluminum, in particulartrimethylaluminum, with water. In general, the oligomeric aluminoxanecompounds obtained are in the form of mixtures of both linear and cyclicchain molecules of various lengths, so that I is to be regarded as amean. The aluminoxane compounds can also be present in admixture withother metal alkyls, usually aluminum alkyls. Aluminoxane preparationssuitable as component (C) are commercially available.

Furthermore modified aluminoxanes in which some of the hydrocarbonradicals have been replaced by hydrogen atoms or alkoxy, aryloxy, siloxyor amide radicals can also be used in place of the aluminoxane compoundsof the formula (X) or (XI) as component (C).

It has been found to be advantageous to use the transition metal complexA) or the iron complex B) and the aluminoxane compounds in such amountsthat the atomic ratio of aluminum from the aluminoxane compoundsincluding any aluminum alkyl still present to the transition metal fromthe transition metal complex (A) is in the range from 1:1 to 2000:1,preferably from 10:1 to 500:1 and in particular in the range from 20:1to 400:1. The atomic ratio of aluminum from the aluminoxane compoundsincluding any aluminum alkyl still present to the iron from the ironcomplex (B) is usually in the range from 1:1 to 2000:1, preferably from10:1 to 500:1 and in particular in the range from 20:1 to 400:1.

A further class of suitable activating components (C) arehydroxyaluminoxanes. These can be prepared, for example, by addition offrom 0.5 to 1.2 equivalents of water, preferably from 0.8 to 1.2equivalents of water, per equivalent of aluminum to an alkylaluminumcompound, in particular triisobutylaluminum, at low temperatures,usually below 0° C. Such compounds and their use in olefinpolymerization are described, for example, in WO 00/24787. The atomicratio of aluminum from the hydroxyaluminoxane compound to the transitionmetal from the transition metal complex (A) or the iron complex (B) isusually in the range from 1:1 to 100:1, preferably from 10:1 to 50:1 andin particular in the range from 20:1 to 40:1. Preference is given tousing a monocyclopentadienyl metall dialkyl compound (A1) or a hafnocenedialkyl compound (A2).

As strong, uncharged Lewis acids, preference is given to compounds ofthe general formula (XII)M^(2D)X^(1D)X^(2D)X^(3D)  (XII)

where

-   -   M^(2D) is an element of group 13 of the Periodic Table of the        Elements, in particular B, Al or Ga, preferably B,    -   X^(1D), X^(2D) and X^(3D) are each hydrogen, C₁-C₁₀-alkyl,        C₆-C₁₅-aryl, alkylaryl, arylalkyl, haloalkyl or haloaryl each        having from 1 to 10 carbon atoms in the alkyl part and from 6 to        20 carbon atoms in the aryl part or fluorine, chlorine, bromine        or iodine, in particular haloaryls, preferably        pentafluorophenyl.

Further examples of strong, uncharged Lewis acids are given in WO00/31090.

Compounds which are particularly useful as component (C) are boranes andboroxins such as trialkylborane, triarylborane or trimethylboroxin.Particular preference is given to using boranes which bear at least twoperfluorinated aryl radicals. Particular preference is given tocompounds of the general formula (XII) in which X^(1D), X^(2D) andX^(3D) are identical, for example triphenylborane,tris(4-fluorophenyl)borane, tris(3,5-difluorophenyl)borane,tris(4-fluoromethylphenyl)borane, tris(pentafluorophenyl)borane,tris(tolyl)borane, tris(3,5-dimethylphenyl)borane,tris(3,5-difluorophenyl)borane or tris(3,4,5-trifluorophenyl)borane.Preference is given to using tris(pentafluorophenyl)borane.

Suitable compounds (C) are preferably prepared by reaction of aluminumor boron compounds of the formula (XII) with water, alcohols, phenolderivatives, thiophenol derivatives or aniline derivatives, withhalogenated and especially perfluorinated alcohols and phenols being ofparticular importance. Examples of particularly useful compounds arepentafluorophenol, 1,1-bis(pentafluorophenyl)methanol and4-hydroxy-2,2′,3,3′,4′,5,5,6,6′-nonafluorobiphenyl. Examples ofcombinations of compounds of the formula (XII) with Broenstedt acidsare, in particular, trimethylaluminum/pentafluorophenol,trimethylaluminum/1-bis(pentafluorophenyl)methanol,trimethylaluminum/4-hydroxy-2,2′,3,3′,4′,5,5′,6,6′-nonafluorobiphenyl,triethylaluminum/pentafluorophenol andtriisobutylaluminum/pentafluorophenol andtriethylaluminum/4,4′-dihydroxy-2,2′,3,3′,5,5′,6,6′-octafluorobiphenylhydrate.

In further suitable aluminum and boron compounds of the formula (XII),R^(1D) is an OH group, such as, for example, in boronic acids andborinic acids. Particular mention may be made of borinic acids havingperfluorinated aryl radicals, for example (C₆F₅)₂BOH.

Strong uncharged Lewis acids suitable as activating compounds (C) alsoinclude the reaction products of the reaction of a boronic acid with twoequivalents of an aluminum trialkyl or the reaction products of thereaction of an aluminum trialkyl with two equivalents of an acidicfluorinated, in particular perfluorinated, carbon compound such aspentafluorophenol or bis(pentafluorophenyl)borinic acid.

Suitable ionic compounds having Lewis-acid cations include salt-likecompounds of the cation of the general formula (XIII)[((M^(3D))^(a+))Q₁Q₂ . . . Q_(z)]^(d+)  (XIII)

where

-   -   M^(3D) is an element of groups 1 to 16 of the Periodic Table of        the Elements,    -   Q₁ to Q_(z) are simply negatively charged radicals such as        C₁-C₂₈-alkyl, C₆-C₁₅-aryl, alkylaryl, arylalkyl, haloalkyl,        haloaryl each having from 6 to 20 carbon atoms in the aryl part        and from 1 to 28 carbon atoms in the alkyl part,        C₃-C₁₀-cycloalkyl which may bear C₁-C₁₀-alkyl groups as        substituents, halogen, C₁-C₂₈-alkoxy, C₆-C₁₅-aryloxy, silyl or        mercaptyl groups,    -   a is an integer from 1 to 6 and    -   z is an integer from 0 to 5,    -   d corresponds to the difference a-z, but d is greater than or        equal to 1.

Particularly useful cations are carbonium cations, oxonium cations andsulfonium cations and also cationic transition metal complexes.Particular mention may be made of the triphenylmethyl cation, the silvercation and the 1,1′-dimethylferrocenyl cation. They preferably havenoncoordinating counterions, in particular boron compounds as are alsomentioned in WO 91/09882, preferably tetrakis(pentafluorophenyl)borate.

Salts having noncoordinating anions can also be prepared by combining aboron or aluminum compound, e.g. an aluminum alkyl, with a secondcompound which can react to link two or more boron or aluminum atoms,e.g. water, and a third compound which forms with the boron or aluminiumcompound an ionizing ionic compound, e.g. triphenylchloromethane, oroptionally a base, preferably an organic nitrogen-containing base, forexample an amine, an aniline derivative or a nitrogen heterocycle. Inaddition, a fourth compound which likewise reacts with the boron oraluminum compound, e.g. pentafluorophenol, can be added.

Ionic compounds containing Brönsted acids as cations preferably likewisehave noncoordinating counterions. As Brönsted acid, particularpreference is given to protonated amine or aniline derivatives.Preferred cations are N,N-dimethylanilinium,N,N-dimethylcyclohexylammonium and N,N-dimethylbenzylammonium and alsoderivatives of the latter two.

Compounds containing anionic boron heterocycles as are described in WO9736937 are also suitable as component (C), in particulardimethylanilinium boratabenzenes or trityl boratabenzenes.

Preferred ionic compounds C) contain borates which bear at least twoperfluorinated aryl radicals. Particular preference is given toN,N-dimethylanilinium tetrakis(pentafluorophenyl)borate and inparticular N,N-dimethylcyclohexylammoniumtetrakis(pentafluorophenyl)borate, N,N-dimethylbenzylammoniumtetrakis(pentafluorophenyl)borate or trityltetrakispentafluorophenylborate.

It is also possible for two or more borate anions to be joined to oneanother, as in the dianion [(C₆F₅)₂B-C₆F₄-B(C₆F₅)₂]²⁻, or the borateanion can be bound via a bridge to a suitable functional group on thesupport surface.

Further suitable activating compounds (C) are listed in WO 00/31090.

The amount of strong, uncharged Lewis acids, ionic compounds havingLewis-acid cations or ionic compounds containing Brönsted acids ascations is preferably from 0.1 to 20 equivalents, more preferably from 1to 10 equivalents and particularly preferably from 1 to 2 equivalents,based on the transition metal complex (A) or the iron complex (B).

Suitable activating compounds (C) also include boron-aluminum compoundssuch as di[bis(pentafluorophenylboroxy)]methylalane. Examples of suchboron-aluminum compounds are those disklosed in WO 99/06414.

It is also possible to use mixtures of all the abovementioned activatingcompounds (C). Preferred mixtures comprise aluminoxanes, in particularmethylaluminoxane, and an ionic compound, in particular one containingthe tetrakis(pentafluorophenyl)borate anion, and/or a strong unchargedLewis acid, in particular tris(pentafluorophenyl)borane or a boroxin.

Both the transition metal complex (A) or the iron complex (B) and theactivating compounds (C) are preferably used in a solvent, preferably anaromatic hydrocarbon having from 6 to 20 carbon atoms, in particularxylenes, toluene, pentane, hexane, heptane or a mixture thereof.

A further possibility is to use an activating compound (C) which cansimultaneously be employed as support (D). Such systems are obtained,for example, from an inorganic oxide treated with zirconium alkoxide andsubsequent chlorination, e.g. by means of carbon tetrachloride. Thepreparation of such systems is described, for example, in WO 01/41920.

Combinations of the preferred embodiments of (C) with the preferredembodiments of (A) and/or (B) are particularly preferred.

As joint activator (C) for the catalyst component (A) and (B),preference is given to using an aluminoxane. Preference is also given tothe combination of salt-like compounds of the cation of the generalformula (XIII), in particular N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, N,N-dimethylcyclohexylammoniumtetrakis(pentafluorophenyl)borate, N,N-dimethylbenzylammoniumtetrakis(pentafluorophenyl)borate or trityltetrakispentafluorophenylborate, as activator (C) for hafnocenes (A2),in particular in combination with an aluminoxane as activator (C) forthe iron complex (B).

Further particularly useful joint activators (C) are the reactionproducts of aluminum compounds of the formula (XII) with perfluorinatedalcohols and phenols.

To enable the transition metal complex (A) and the iron complex (B) tobe used in polymerization processes in the gas phase or in suspension,it is often advantageous to use the complexes in the form of a solid,i.e. for them to be applied to a solid support (D). Furthermore, thesupported complexes have a high productivity. The transition metalcomplexes (A) and/or the iron complex (B) can therefore also optionallybe immobilized on an organic or inorganic support (D) and be used insupported form in the polymerization. This enables, for example,deposits in the reactor to be avoided and the polymer morphology to becontrolled. As support materials, preference is given to using silicagel, magnesium chloride, aluminum oxide, mesoporous materials,aluminosilicates, hydrotalcites and organic polymers such aspolyethylene, polypropylene, polystyrene, polytetrafluoroethylene orpolymers bearing polar functional groups, for example copolymers ofethene and acrylic esters, acrolein or vinyl acetate.

Particular preference is given to a catalyst system comprising at leastone transition metal complex (A), at least one iron complex (B), atleast one activating compound (C) and at least one support component(D).

The preferred catalyst composition according to the invention comprisesone or more support components. It is possible for both the transitionmetal component (A) and the iron complex (B) to be supported, or onlyone of the two components can be supported. In a preferred embodiment,both the components (A) and (B) are supported. The two components (A)and (B) can in this case be applied to different supports or together ona joint support. The components (A) and (B) are preferably applied to ajoint support in order to ensure a relatively close spatial proximity ofthe various catalyst centers and thus to ensure good mixing of thedifferent polymers formed.

To prepare the catalyst systems of the invention, preference is given toimmobilizing one of the components (A) and one of the components (B)and/or activator (C) or the support (D) by physisorption or else bymeans of a chemical reaction, i.e. covalent binding of the components,with reactive groups on the support surface.

The order in which support component D), transition metal complex (A),iron complex (B) and the activating compounds (C) are combined is inprinciple immaterial. After the individual process steps, the variousintermediates can be washed with suitable inert solvents such asaliphatic or aromatic hydrocarbons.

Transition metal complex (A), iron complex (B) and the activatingcompound (C) can be immobilized independently of one another, e.g. insuccession or simultaneously. Thus, the support component (D) canfirstly be brought into contact with the activating compound orcompounds (C) or the support component (D) can firstly be brought intocontact with the transition metal complex (A) and/or the iron complex(B). Preactivation of the transition metal complex A) by means of one ormore activating compounds (C) prior to mixing with the support (D) isalso possible. The iron component can, for example, be reactedsimultaneously with the transition metal complex with the activatingcompound (C), or can be preactivated separately by means of the latter.The preactivated iron complex (B) can be applied to the support beforeor after the preactivated transition metal complex (A). In one possibleembodiment, the transition metal complex (A) and/or the iron complex (B)can also be prepared in the presence of the support material. A furthermethod of immobilization is prepolymerization of the catalyst systemwith or without prior application to a support.

The immobilization is generally carried out in an inert solvent whichcan be removed by filtration or evaporation after the immobilization.After the individual process steps, the solid can be washed withsuitably inert solvents such as aliphatic or aromatic hydrocarbons anddried. However, the use of the still moist, supported catalyst is alsopossible.

In a preferred method of preparing the supported catalyst system, atleast one iron complex (B) is brought into contact with an activatedcompound (C) and subsequently mixed with the dehydrated or passivatedsupport material (D). The transition metal complex (A) is likewisebrought into contact with at least one activating compound (C) in asuitable solvent, preferably giving a soluble reaction product, anadduct or a mixture. The preparation obtained in this way is then mixedwith the immobilized iron complex, which is used directly or after thesolvent has been separated off, and the solvent is completely or partlyremoved. The resulting supported catalyst system is preferably dried toensure that all or most of the solvent is removed from the pores of thesupport material. The supported catalyst is preferably obtained as afree-flowing powder. Examples of the industrial implementation of theabove process are described in WO 96/00243, WO 98/40419 or WO 00/05277.A further preferred embodiment comprises firstly producing theactivating compound (C) on the support component (D) and subsequentlybringing this supported compound into contact with the transition metalcomplex (A) and the iron complex (B).

As support component (D), preference is given to using finely dividedsupports which can be any organic or inorganic solid. In particular, thesupport component (D) can be a porous support such as talc, a sheetsilicate such as montmorillonite, mica or an inorganic oxide or a finelydivided polymer powder (e.g. polyolefin or a polymer having polarfunctional groups).

The support materials used preferably have a specific surface area inthe range from 10 to 1000 m²/g, a pore volume in the range from 0.1 to 5ml/g and a mean particle size of from 1 to 500 μm. Preference is givento supports having a specific surface area in the range from 50 to 700m²/g, a pore volume in the range from 0.4 to 3.5 ml/g and a meanparticle size in the range from 5 to 350 μm. Particular preference isgiven to supports having a specific surface area in the range from 200to 550 m²/g, a pore volume in the range from 0.5 to 3.0 ml/g and a meanparticle size of from 10 to 150 μm.

The transition metal complex (A) is preferably applied in such an amountthat the concentration of the transition metal from the transition metalcomplex (A) in the finished catalyst system is from 1 to 200 μmol,preferably from 5 to 100 μmol and particularly preferably from 10 to 70μmol, per g of support (D). The iron complex (B) is preferably appliedin such an amount that the concentration of iron from the iron complex(B) in the finished catalyst system is from 1 to 200 μmol, preferablyfrom 5 to 100 μmol and particularly preferably from 10 to 70 μmol, per gof support (D).

The inorganic support can be subjected to a thermal treatment, e.g. toremove adsorbed water. Such a drying treatment is generally carried outat temperatures in the range from 50 to 1000° C., preferably from 100 to600° C., with drying at from 100 to 200° C. preferably being carried outunder reduced pressure and/or under a blanket of inert gas (e.g.nitrogen), or the inorganic support can be calcined at temperatures offrom 200 to 1000° C. to produce the desired structure of the solidand/or set the desired OH concentration on the surface. The support canalso be treated chemically using customary dessicants such as metalalkyls preferably aluminum alkyls, chlorosilanes or SiCl₄, or elsemethylaluminoxane. Appropriate treatment methods are described, forexample, in WO 00/31090.

The inorganic support material can also be chemically modified. Forexample, treatment of silica gel with NH₄SiF₆ or other fluorinatingagents leads to fluorination of the silica gel surface, or treatment ofsilica gels with silanes containing nitrogen-, fluorine- orsulfur-containing groups leads to correspondingly modified silica gelsurfaces.

Organic support materials such as finely divided polyolefin powders(e.g. polyethylene, polypropylene or polystyrene) can also be used andare preferably likewise freed of adhering moisture, solvent residues orother impurities by appropriate purification and drying operationsbefore use. It is also possible to use functionalized polymer supports,e.g. ones based on polystyrene, polyethylene, polypropylene orpolybutylene, via whose functional groups, for example ammonium orhydroxy groups, at least one of the catalyst components can beimmobilized. It is also possible to use polymer blends.

Inorganic oxides suitable as support component (D) may be found amongthe oxides of elements of groups 2, 3, 4, 5, 13, 14, 15 and 16 of thePeriodic Table of the Elements. Examples of oxides preferred as supportsinclude silicon dioxide, aluminum oxide and mixed oxides of the elementscalcium, aluminum, silicon, magnesium or titanium and also correspondingoxide mixtures. Other inorganic oxides which can be used alone or incombination with the abovementioned preferred oxidic supports are, forexample, MgO, CaO, AIPO₄, ZrO₂, TiO₂, B₂O₃ or mixtures thereof.

Further preferred inorganic support materials are inorganic halides suchas MgCl₂ or carbonates such as Na₂CO₃, K₂CO₃, CaCO₃, MgCO₃, sulfatessuch as Na₂SO₄, Al₂(SO₄)₃, BaSO₄, nitrates such as KNO₃, Mg(NO₃)₂ orAl(NO₃)_(3.)

As solid support materials (D) for catalysts for olefin polymerization,preference is given to using silica gels since particles whose size andstructure make them suitable as supports for olefin polymerization canbe produced from this material. Spray-dried silica gels, which arespherical agglomerates of relatively small granular particles, i.e.primary particles, have been found to be particularly useful. The silicagels can be dried and/or calcined before use.

Further preferred supports (D) are hydrotalcites and calcinedhydrotalcites. In mineralogy, hydrotalcite is a natural mineral havingthe ideal formulaMg₆Al₂(OH)₁₆CO₃·4 H₂O

whose structure is derived from that of brucite Mg(OH)₂. Brucitecrystallizes in a sheet structure with the metal ions in octahederalholes between two layers of close-packed hydroxyl ions, with only everysecond layer of the octahederal holes being occupied. In hydrotalcite,some magnesium ions are replaced by aluminum ions, as a result of whichthe packet of layers gains a positive charge. This is balanced by theanions which are located together with water of crystallization in thelayers in-between.

Such sheet structures are found not only inmagnesium-aluminum-hydroxides, but generally in mixed metal hydroxidesof the general formulaM(II)_(2x) ²⁺M(III)₂ ³⁺(OH)_(4x+4)·A_(2/n) ^(n−)·z H₂O

which have a sheet structure and in which M(II) is a divalent metal suchas Mg, Zn, Cu, Ni, Co, Mn, Ca and/or Fe and M(III) is a trivalent metalsuch as Al, Fe, Co, Mn, La, Ce and/or Cr, x is a number from 0.5 to 10in steps of 0.5, A is an interstitial anion and n is the charge on theinterstitial anion which can be from 1 to 8, usually from 1 to 4, and zis an integer from 1 to 6, in particular from 2 to 4. Possibleinterstitial anions are organic anions such as alkoxide anions, alkylether sulfates, aryl ether sulfates or glycol ether sulfates, inorganicanions such as, in particular, carbonate, hydrogen carbonate, nitrate,chloride, sulfate or B(OH)₄ ⁻ or polyoxometal anions such as Mo₇O₂₄ ⁶⁻or V₁₀O₂₈ ⁶⁻. However, a mixture of a plurality of such anions is alsopossible.

Accordingly, all such mixed metal hydroxides having a sheet structureshould be regarded as hydrotalcites for the purposes of the presentinvention.

Calcined hydrotalcites can be prepared from hydrotalcites bycalcination, i.e. heating, by means of which, inter alia, the desiredhydroxide group content can be set. In addition, the crystal structurealso changes. The preparation of the calcined hydrotalcites usedaccording to the invention is usually carried out at temperatures above180° C. Preference is given to calcination for a period of from 3 to 24hours at temperatures of from 250° C. to 1000° C., in particular from400° C. to 700° C. It is possible for air or inert gas to be passed overthe solid or for a vacuum to be applied at the same time.

On heating, the natural or synthetic hydrotalcites firstly give offwater, i.e. drying occurs. On further heating, the actual calcination,the metal hydroxides are converted into the metal oxides by eliminationof hydroxyl groups and interstitial anions; OH groups or interstitialanions such as carbonate can also still be present in the calcinedhydrotalcites. A measure of this is the loss on ignition. This is theweight loss experienced by a sample which is heated in two steps firstlyfor 30 minutes at 200° C. in a drying oven and then for 1 hour at 950°C. in a muffle furnace.

The calcined hydrotalcites used as component (D) are thus mixed oxidesof the divalent and trivalent metals M(II) and M(III), with the molarratio of M(II) to M(III) generally being in the range from 0.5 to 10,preferably from 0.75 to 8 and in particular from 1 to 4. Furthermore,normal amounts of impurities, for example Si, Fe, Na, Ca or Ti and alsochlorides and sulfates, can also be present.

Preferred calcined hydrotalcites (D) are mixed oxides in which M(II) ismagnesium and M(III) is aluminum. Such aluminum-magnesium mixed oxidesare obtainable from Condea Chemie GmbH (now Sasol Chemie), Hamburg underthe trade name Puralox Mg.

Preference is also given to calcined hydrotalcites in which thestructural transformation is complete or virtually complete.Calcination, i.e. transformation of the structure, can be confirmed, forexample, by means of X-ray diffraction patterns.

The hydrotalcites, calcined hydrotalcites or silica gels used aregenerally used as finely divided powders having a mean particle diameterD50 of from 5 to 200 μm, preferably from 10 to 150 μm, particularlypreferably from 15 to 100 μm and in particular from 20 to 70 μm, andusually have pore volumes of from 0.1 to 10 cm³/g, preferably from 0.2to 5 cm³/g, and specific surface areas of from 30 to 1000 m²/g,preferably from 50 to 800 m²/g and in particular from 100 to 600 m²/g.The transition metal complex (A) is preferably applied in such an amountthat the concentration of the transition metal from the transition metalcomplex (A) in the finished catalyst system is from 1 to 100 μmol,preferably from 5 to 80 μmol and particularly preferably from 10 to 60μmol, per g of support (D).

The catalyst system may further comprise, as additional component (E), ametal compound of the general formula (XX),M^(G)(R^(1G))_(r)G(R^(2G))_(s)G(R^(3G))_(t)G  (XX)

where

-   -   M^(G) is Li, Na, K, Be, Mg, Ca, Sr, Ba, boron, aluminum,        gallium, indium, thallium, zinc, in particular Li, Na, K, Mg,        boron, aluminum or Zn,    -   R^(1G) is hydrogen, C₁-C₁₀-alkyl, C₆-C₁₅-aryl, alkylaryl or        arylalkyl each having from 1 to 10 carbon atoms in the alkyl        part and from 6 to 20 carbon atoms in the aryl part,    -   R^(2G) and R^(3G) are each hydrogen, halogen, C₁-C₁₀-alkyl,        C₆-C₁₅-aryl, alkylaryl, arylalkyl or alkoxy each having from 1        to 20 carbon atoms in the alkyl part and from 6 to 20 carbon        atoms in the aryl part, or alkoxy together with C₁-C₁₀-alkyl or        C₆-C₁₅-aryl,    -   r^(G) is an integer from 1 to 3    -   and    -   s^(G) and t^(G) are integers from 0 to 2, with the sum        r^(G)+s^(G)+t^(G) corresponding to the valence of M^(G), where        the component (E) is usually not identical to the component (C).        It is also possible to use mixtures of various metal compounds        of the formula (XX).

Among the metal compounds of the general formula (XX), preference isgiven to those in which

-   -   M^(G) is lithium, magnesium, boron or aluminum and    -   R^(1G) is C₁-C₂₀-alkyl.

Particularly preferred metal compounds of the formula (XX) aremethyllithium, ethyllithium, n-butyllithium, methylmagnesium chloride,methylmagnesium bromide, ethylmagnesium chloride, ethylmagnesiumbromide, butylmagnesium chloride, dimethylmagnesium, diethylmagnesium,dibutylmagnesium, n-butyl-n-octylmagnesium, n-butyl-n-heptylmagnesium,in particular n-butyl-n-octylmagnesium, tri-n-hexylaluminum,triisobutylaluminum, tri-n-butylaluminum, triethylaluminum,dimethylaluminum chloride, dimethylaluminum fluoride, methylaluminumdichloride, methylaluminum sesquichloride, diethylaluminum chloride andtrimethylaluminum and mixtures thereof. The partial hydrolysis productsof aluminum alkyls with alcohols can also be used.

When a metal compound (E) is used, it is preferably present in thecatalyst system in such an amount that the molar ratio of M^(G) fromformula (XX) to the sum of the transition metals from the transitionmetal complex (A) and the iron complex (B) is from 3000:1 to 0.1:1,preferably from 800:1 to 0.2:1 and particularly preferably from 100:1 to1:1.

In general, the metal compound (E) of the general formula (XX) is usedas constituent of a catalyst system for the polymerization orcopolymerization of olefins. Here, the metal compound (E) can, forexample, be used for preparing a catalyst solid comprising the support(D) and/or be added during or shortly before the polymerization. Themetal compounds (E) used can be identical or different. It is alsopossible, particularly when the catalyst solid contains no activatingcomponent (C), for the catalyst system to further comprise, in additionto the catalyst solid, one or more activating compounds (C) which areidentical to or different from any compounds (E) present in the catalystsolid.

The component E) can likewise be reacted in any order with thecomponents (A), (B) and optionally (C) and (D). The component (A) can,for example, be brought into contact with the component(s) (C) and/or(D) either before or after being brought into contact with the olefinsto be polymerized. Preactivation by means of one or more components (C)prior to mixing with the olefin and further addition of the same oranother component (C) and/or (D) after this mixture has been broughtinto contact with the olefin is also possible. Preactivation isgenerally carried out at temperatures of 10-100° C., preferably 20-80°C.

In another preferred embodiment, a catalyst solid is prepared from thecomponents (A), (B), (C) and (D) as described above and this is broughtinto contact with the component (E) during, at the commencement of orshortly before the polymerization.

Preference is given to firstly bringing (E) into contact with theα-olefin to be polymerized and subsequently adding the catalyst solidcomprising the components (A), (B), (C) and (D) as described above.

In a further, preferred embodiment, the support (D) is firstly broughtinto contact with the component (E), and the components (A) and (B) andany further activator (C) are then dealt with as described above.

It is also possible for the catalyst system firstly to be prepolymerizedwith α-olefins, preferably linear C₂-C₁₀-1-alkenes and in particularethylene or propylene, and the resulting prepolymerized catalyst solidthen to be used in the actual polymerization. The mass ratio of catalystsolid used in the prepolymerization to a monomer polymerized onto it isusually in the range from 1:0.1 to 1:1000, preferably from 1:1 to 1:200.

Furthermore, a small amount of an olefin, preferably an α-olefin, forexample vinylcyclohexane, styrene or phenyldimethylvinylsilane, asmodifying component, an antistatic or a suitable inert compound such asa wax or oil can be added as additive during or after the preparation ofthe catalyst system. The molar ratio of additives to the sum oftransition metal compound (A) and iron complex (B) is usually from1:1000 to 1000:1, preferably from 1:5 to 20:1.

The catalyst composition or catalyst system of the invention is suitablefor preparing the polyethylene of the invention, which has advantageoususe and processing properties.

To prepare the polyethylene of the invention, the ethylene ispolymerized as described above with α-olefins having from 3 to 12 carbonatoms.

In the copolymerization process of the invention, ethylene ispolymerized with α-olefins having from 3 to 12 carbon atoms. Preferredα-olefins are linear or branched C₂-C₁₂-1-alkenes, in particular linearC₂-C₁₀-1-alkenes such as ethene, propene, 1-butene, 1-pentene, 1-hexene,1-heptene, 1-octene, 1-decene or branched C₂-C₁₀-1-alkenes such as4-methyl-1-pentene. Particularly preferred α-olefins areC₄-C₁₂-1-alkenes, in particular linear C₆-C₁₀-1-alkenes. It is alsopossible to polymerize mixtures of various α-olefins. Preference isgiven to polymerizing at least one α-olefin selected from the groupconsisting of ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene,1-octene and 1-decene. Monomer mixtures containing at least 50 mol % ofethene are preferably used.

The process of the invention for polymerizing ethylene with α-olefinscan be carried out using all industrially known polymerization methodsat temperatures in the range from −60 to 350° C., preferably from 0 to200° C. and particularly preferably from 25 to 150° C., and underpressures of from 0.5 to 4000 bar, preferably from 1 to 100 bar andparticularly preferably from 3 to 40 bar. The polymerization can becarried out in a known manner in bulk, in suspension, in the gas phaseor in a supercritical medium in the customary reactors used for thepolymerization of olefins. It can be carried out batchwise or preferablycontinuously in one or more stages. High-pressure polymerizationprocesses in tube reactors or autoclaves, solution processes, suspensionprocesses, stirred gas-phase processes and gas-phase fluidized-bedprocesses are all possible.

The polymerizations are usually carried out at temperatures in the rangefrom −60 to 350° C., preferably in the range from 20 to 300° C., andunder pressures of from 0.5 to 4000 bar. The mean residence times areusually from 0.5 to 5 hours, preferably from 0.5 to 3 hours. Theadvantageous pressure and temperature ranges for carrying out thepolymerizations usually depend on the polymerization method. In the caseof high-pressure polymerization processes, which are customarily carriedout at pressures of from 1000 to 4000 bar, in particular from 2000 to3500 bar, high polymerization temperatures are generally also set.Advantageous temperature ranges for these high-pressure polymerizationprocesses are from 200 to 320° C., in particular from 220 to 290° C. Inthe case of low-pressure polymerization processes, it is usual to set atemperature which is at least a few degrees below the softeningtemperature of the polymer. In particular, temperatures of from 50 to180° C., preferably from 70 to 120° C., are set in these polymerizationprocesses. In the case of suspension polymerizations, the polymerizationis usually carried out in a suspension medium, preferably an inerthydrocarbon such as isobutane or mixtures of hydrocarbons or else in themonomers themselves. The polymerization temperatures are generally inthe range from −20 to 115° C., and the pressure is generally in therange from 1 to 100 bar. The solids content of the suspension isgenerally in the range from 10 to 80%. The polymerization can be carriedout either batchwise, e.g. in stirring autoclaves, or continuously, e.g.in tube reactors, preferably in loop reactors. Particular preference isgiven to employing the Phillips PF process as described in U.S. Pat. No.3,242,150 and U.S. Pat. No. 3,248,179. The gas-phase polymerization isgenerally carried out in the range from 30 to 125° C. at pressures offrom 1 to 50 bar.

Among the abovementioned polymerization processes, particular preferenceis given to gas-phase polymerization, in particular in gas-phasefluidized-bed reactors, solution polymerization and suspensionpolymerization, in particular in loop reactors and stirred tankreactors. The gas-phase polymerization can also be carried out in thecondensed or supercondensed mode, in which part of the circulating gasis cooled to below the dew point and is recirculated as a two-phasemixture to the reactor. Furthermore, it is possible to use a multizonereactor in which the two polymerization zones are linked to one anotherand the polymer is passed alternately through these two zones a numberof times. The two zones can also have different polymerizationconditions. Such a reactor is described, for example, in WO 97/04015.The different or identical polymerization processes can also, ifdesired, be connected in series so as to form a polymerization cascade,for example as in the Hostalen® process. A parallel reactor arrangementusing two or more identical or different processes is also possible.Furthermore, molar mass regulators, for example hydrogen, or customaryadditives such as antistatics can also be used in the polymerizations.

The polymerization is preferably carried out in a single reactor, inparticular in a gas-phase reactor. The polymerization of ethylene withα-olefins having from 3 to 12 carbon atoms gives the polyethylene of theinvention when the catalyst of the invention is used. The polyethylenepowder obtained directly from the reactor displays a very highhomogeneity, so that, unlike the case of cascade processes, subsequentextrusion is not necessary in order to obtain a homogeneous product.

The production of polymer blends by intimate mixing of individualcomponents, for example by melt extrusion in an extruder or kneader(cf., for example, “Polymer Blends” in Ullmann's Encyclopedia ofIndustrial Chemistry, 6^(th) Edition, 1998, Electronic Release), isoften accompanied by particular difficulties. The melt viscosities ofthe high and low molecular weight components of a bimodal polyethyleneblend are extremely different. While the low molecular weight componentis quite fluid at the customary temperatures of about 190-210° C. usedfor producing the blends, the high molecular weight component is onlysoftened (“lentil soup”). Homogeneous mixing of the two components istherefore for very difficult. In addition, it is known that the highmolecular weight component can easily be damaged as a result of thermalstress and by shear forces in the extruder, so that the properties ofthe blend are adversely affected. The mixing quality of suchpolyethylene blends is therefore often unsatisfactory.

The mixing quality of the polyethylene powder obtained directly from thereactor can be tested by assessing thin slices (“microtome sections”) ofa sample under an optical microscope. Inhomogenities show up in the formof specks or “white spots”. The specs or “white spots” are predominantlyhigh molecular weight, high-viscosity particles in a low-viscositymatrix (cf., for example, U. Burkhardt et al. in “Aufbereiten vonPolymeren mit neuartigen Eigenschaften”, VDI-Verlag, Düsseldorf 1995, p.71). Such inclusions can reach a size of up to 300 μm, cause stresscracks and result in brittle failure of components. The better themixing quality of a polymer, the fewer and smaller are these inclusionsobserved. The mixing quality of a polymer is determined quantitativelyin accordance with ISO 13949. According to the measurement method, amicrotome section is prepared from a sample of the polymer, the numberand size of these inclusions are counted and a grade is determined forthe mixing quality of the polymer according to a set assessment scheme.The mixing quality in the polyethylene directly obtained from thereactor, the polymer powder without extrusion is preferably less than 3.

The preparation of the polyethylene of the invention in the reactorreduces the energy consumption, requires no subsequent blendingprocesses and makes simple control of the molecular weight distributionsand the molecular weight fractions of the various polymers possible. Inaddition, good mixing of the polyethylene is achieved.

The following examples illustrate the invention without restricting thescope of the invention.

The measured values described were determined in the following way:

NMR samples were placed in tubes under inert gas and, if appropriate,melted. The solvent signals served as internal standard in the ¹H- and¹³C-NMR spectra and their chemical shift was converted into the valuesrelative to TMS.

The vinyl group content is determined by means of IR in accordance withASTM D 6248-98. The branches/1000 carbon atoms are determined by meansof ¹³C-NMR, as described by James. C. Randall, JMS-REV. Macromol. Chem.Phys., C29 (2&3), 201-317 (1989), and are based on the total content ofCH₃ groups/1000 carbon atoms including end groups. The side chainslarger than CH₃ and especially ethyl, butyl and hexyl side chainbranches/1000 carbon atoms excluding end groups are likewise determinedin this way.

The degree of branching in the individual polymer fractions isdetermined by the method of Holtrup (W. Holtrup, Makromol. Chem. 178,2335 (1977)) coupled with ¹³C-NMR. as described by James. C. Randall,JMS-REV. Macromol. Chem. Phys., C29 (2&3), 201-317 (1989)

The density [g/cm³] was determined in accordance with ISO 1183.

The determination of the molar mass distributions and the means Mn, Mw,and Mw/Mn derived therefrom was carried out by means of high-temperaturegel permeation chromatography on a WATERS 150 C using a method based onDIN 55672 and the following columns connected in series: 3× SHODEX AT806 MS, 1× SHODEX UT 807 and 1× SHODEX AT-G under the followingconditions: solvent: 1,2,4-trichlorobenzene (stabilized with 0.025% byweight of 2,6-di-tert-butyl-4-methylphenol), flow: 1 ml/min, 500 μlinjection volume, temperature: 135° C., calibration using PE Standards.Evaluation was carried out using WIN-GPC.

For the purposes of the present invention, the expression “HLMI” refers,as is generally known, to the “high load melt flow rate” and is alwaysdetermined at 190° C. under a load of 21.6 kg (190° C./21.6 kg) inaccordance with ISO 1133.

The haze, as determined according to ASTM D 1003-00 on a BYK GardenerHaze Guard Plus Device on at least 5 pieces of film 10×10 cm with athickness of 1 mm.

The impact resistance was determined according to the instrument fallingweight impact test according to ISO 6603 at −20 ° C.

The stress crack resistance (full notch creep test (FNCT)) wasdetermined according to ISO DIS2 16770 at a pressure of 3.5 Mbar at 80°C. in a 2% by weight solution of Akropal N (N=10) in water.

The spiral flow test was measured on a Demag ET100-310 with a closingpressure of 100 t and a 3 mm die and with a stock temperature of 250°C., an injection pressure of 1000 bar, a screw speed of 90 mm/s, a moldtemperature of 30° C. and wall thickness 2 mm.

Abbreviations in the table below:

-   -   Cat. Catalyst    -   T(poly) Polymerisation temperature    -   M_(w) Weight average molar mass    -   M_(n) Number average molar mass    -   Density Polymer density    -   Vinyl/1000C refers to the amount of Vinyl groups per 1000 carbon        atoms    -   b/1000C refers to branches/1000 carbon atoms, which is the        amount of CH₃/1000 carbon atoms including end groups    -   br in 15% PE hmw refers to the 15% by weight of the polyethylene        having the highest molar masses with a degree of branches of        side chains larger than CH₃/1000 carbon atoms excluding end        groups    -   Prod. Productivity of the catalyst in g of polymer obtained per        g of catalyst used per hour    -   Impact Impact resistance as determined according to the        instrument falling weight impact test according to ISO 6603 at        −20° C.        Preparation of the Individual Components

Bis(n-butylcyclopentadienyl)hafnium dichloride is commercially availablefrom Crompton.

2,6-Bis[1-(2,4-dichloro-6-methylphenylimino)ethyl]pyridine iron(II)dichloride was prepared according to the method of Qian et al.,Organometallics 2003, 22, 4312-4321. Here, 65.6 g of2,6-diacetylpyridine (0.4 mol), 170 g of 2,4-dichloro-6-methylaniline(0.483 mol), 32 g of silica gel type 135 and 160 g of molecular sieves(4 Å) were stirred in 1500 ml of toluene at 80° C. for 5 hours and afurther 32 g of silica gel type 135 and 160 g of molecular sieves (4 Å)were subsequently added. The mixture was stirred at 80° C. for a further8 hours, the insoluble solid was filtered off and washed twice withtoluene. The solvent was distilled off from the filtrate obtained inthis way, the residue was admixed with 200 ml of methanol andsubsequently stirred at 55° C. for 1 hour. The suspension formed in thisway was filtered and the solid obtained was washed with methanol andfreed of the solvent. This gave 95 g of2,6-Bis[1-(2,4-dichloro-6-methylphenylimino)ethyl]-pyridine in 47%yield. The reaction with iron(II) chloride was carried out as describedby Qian et al., Organometallics 2003, 22, 4312-4321.

Preparation of the Mixed Catalyst Systems

Example 1

a) Support Pretreatment

XPO-2107, a spray-dried silica gel from Grace, was baked at 600° C. for6 hours.

b) Preparation of the Mixed Catalyst Systems

A mixture of 1.43 g (2.37 mmol) of2,6-Bis[1-(2,4-dichloro-6-methylphenylimino)ethyl]pyridine iron(II)dichloride, 9.98 g of bis(n-butylcyclopentadienyl)hafnium dichloride and443 ml of MAO (4.75 M in toluene, 2.1 mol) was stirred at roomtemperature for 1 h and subsequently added while stirring to 338 g ofthe pretreated support material a) in 500 ml of toluene. The resultingsolid gave 778.4 g of catalyst which still contained 23.9% by weight ofsolvent (based on the total weight and calculated on the basis ofcomplete application of all components to the support).

Polymerization of the Catalysts

The polymerization was carried out in a fluidized-bed reactor having adiameter of 0.5 m and an overall pressure of 20 bar. The polymerizationtemperature was 95° C. using the catalyst of example 1, which was fed ata rate of 38.97 g per h to the reactor. Ethylene was fed to the reactorat a rate of 40.7 kg per h, 1-hexene at a rate of 410 g per h andhydrogen at 2.1 l per h. Also 4.62 kg propane per h, 0.33 kg nitrogenper h and 0.5 g triisobutylaluminium per h were fed to the reactor.Polymer was discharged at 30.1 kg/h. The properties of the polymersobtained are summarized in Table 1.

Comparative Example 1

A Ziegler catalyst was prepared as described in EP-A-739937 andpolymerization was carried out in a suspension cascade usingethylene/hydrogen in the 1st reactor and ethylene/1-butene with 0.8% byweight of 1-butene in the 2nd reactor. The product data are shown inTable 1.

TABLE 1 Cat. Prod. HLMI Mw density Vinyl/ branches/ br in 15% from Ex.[g/g] [g/10 min] [g/mol] M_(w)/M_(n) [g/cm³] 1000C 1000C PE hmw 1 3792109 99000 7.9 0.953 1.3 3.9 5 C1 75 116300 10 0.953 0.12 1 0.5

The polymers were each formed into small plates of 1 mm thickness on anEngel injection molding machine. The extrusion temperature was 225° C.,the screw speed 116 turns per min and an injection speed of 50 mm/s. Theholding time was 20 s, the holding pressure 687 bar.

TABLE 2 Properties of the polyethylenes Example 1 V1 Spiral length, 250°C. [cm] 47.6 36 FNCT (3.5 MPa, 80°) [h] 7.4 1.3 Haze [%] 90.80 94.20Impact (−20° C.) [J] 12.42 11.21

1. A polyethylene which comprises ethylene homopolymers, copolymers ofethylene with 1-alkenes or mixtures thereof, having a molar massdistribution width M_(w)/M_(n) of from 3 to 30, a density of from 0.945to 0.965 g/cm³, a weight average molar mass M_(w) of from 50,000 g/molto 200,000 g/mol, an HLMI of from 50 to 200 g/10 min, at least 0.2 vinylgroups/1000 carbon atoms and has from 0.1 to 15 branches/1000 carbonatoms, wherein the 1 to 15% by weight of the polyethylene having thehighest molar masses have a degree of branching of more than 1 branch ofside chains larger than CH₃/1000 carbon atoms, and the 5-50% by weightof the polyethylene having the lowest molar masses have a degree ofbranching of less than 10 branches/1000 carbon atoms.
 2. Thepolyethylene according to claim 1 comprising an at least bimodal shortchain branching distribution.
 3. The polyethylene according to claim 1wherein the degree of branching is from 0.2 to 8 branches/1000 carbonatoms.
 4. The polyethylene according to claim 1 which has been preparedin a single reactor.
 5. An injection molding comprising a polyethylene,the polyethylene comprising ethylene homopolymers, copolymers ofethylene with 1-alkenes or mixtures thereof, having a molar massdistribution width M_(w)/M_(n) of from 3 to 30, a density of from 0.945to 0.965 g/cm³, a weight average molar mass M_(w) of from 50,000 g/molto 200,000 g/mol, an HLMI of from 50 to 200 g/10 min, at least 0.2 vinylgroups/1000 carbon atoms and has from 0.1 to 15 branches/1000 carbonatoms, wherein the 1 to 15% by weight of the polyethylene having thehighest molar masses have a degree of branching of more than 1 branch ofside chains larger than CH₃/1000 carbon atoms, and the 5-50% by weightof the polyethylene having the lowest molar masses have a degree ofbranching of less than 10 branches/1000 carbon atoms.
 6. The injectionmolding according to claim 5, with a haze as determined according toASTM D 1003-00 of less than 94%.
 7. The injection molding according toclaim 5 with a stress cracking resistance (FNCT) as determined accordingto ISO DIS2 16770 at a pressure of 3.5 Mbar at 80° C. in a 2% by weightsolution of Akropal N (N=10) in water, of at least 5 h.
 8. The injectionmolding according to claim 5, wherein the injection molding is a cap,closure, screw cap, screw closure, tube shoulder or engineering part. 9.The injection molding according to claim 5 wherein the injection moldingis a screw cap.
 10. The polyethylene of claim 1 wherein the HLMI is from70 to 150 g/10 min.